Ste 120
Palo Alto, CA 94304
Fax: (650) 497-8422
The care I provide is specifically tailored to each individual child. I love getting to know and image my patient’s heart, and to understand what is unique about it. The relationship I build with parents is centered on trust and open communication. I see parents as my partners in the care of their child.
The excellent quality of care we provide means I can look a parent in the eye and tell them they are getting the very best, whether it’s one of the best pediatric cardiac surgeons in the world (true for all our cardiac surgeons!) or any other member of our care team. Most memorable to me are the moments where I witness the staggering strength and beauty of the love a parent has for their child. It always awes me and sustains my faith in the work we do here.
University of Texas Medical Branch Registrar, Galveston, TX, 05/31/1987
University of Chicago Pediatric Residency, Chicago, IL, 06/30/1990
CS Mott Children's Hospital Pediatric Cardiology, Ann Arbor, MI, 06/30/1993
Pediatric Cardiology, American Board of Pediatrics
BACKGROUND: Little is known about the early time course of biventricular function and mechanics after tetralogy of Fallot (TOF) repair. We sought to evaluate and describe the evolution of the right ventricle (RV) after TOF repair in young infants and children using conventional echocardiographic parameters and global longitudinal strain (GLS).METHODS: A retrospective review was performed of all patients with TOF and pulmonary stenosis who underwent repair from January 2002 to September 2015 and had at least 3 serial postsurgical echocardiograms spanning from infancy to early childhood (<8 years). Student's t test was performed to compare patients who underwent valve sparing (VS) versus transannular patch (TAP) repair. ANOVA was used to track measures of ventricular systolic function over time.RESULTS: We analyzed 151 echocardiograms performed on 42 patients. Pulmonary regurgitation (PR, moderate or severe) and the RV to left ventricular (LV) basal dimension ratio were higher in TAP patients (P<.04 at all-time points). Along with a significant increase in RV basal diameter Z-score in the TAP group (P<.001), there was an improvement in RV and LV GLS over time in both groups (P<.001). The LV GLS at last follow-up was lower in patients who underwent reoperation than those who did not (P=.050). LV GLS at the last follow-up echocardiogram was lower in patients with significant PR than those without (P<.001).CONCLUSIONS: Ventricular function appeared improve over time from the initial postoperative period in TOF patients. TAP repair was associated with a progressively higher RV/LV ratio in young children. GLS and RV/LV basal diameter ratio may be useful when following young children after TOF repair. Further research is necessary to understand the trajectory of ventricular functional and volumetric changes in young children in order to provide the most effective lifetime management of patients with TOF.
View details for PubMedID 30989806
OBJECTIVES: The primary objective was to describe the early "natural history" of pulmonary hypertension (PH) in the premature population. The secondary objective was to describe factors associated with poor outcomes in the premature population with PH at 36 weeks post-menstrual age (PMA).STUDY DESIGN: Retrospective chart review of patients followed at our institution from 2000 to 2017 with echocardiographic (ECHO) evidence of PH at 36 weeks PMA, and born32 weeks estimated gestational age (GA). Cox regression was used for survival analysis.RESULTS: Sixty-one patients with PH (26.51.5 weeks at birth) were included. All PH patients had bronchopulmonary dysplasia (BPD), with 89% considered severe; 38% were small for gestational age. Necrotizing enterocolitis requiring surgery was common (25%). Use of post-natal steroids (HR 11.02, p=0.01) and increased severity of PH (HR 1.05, p<0.001) were associated with mortality. Pulmonary vein stenosis (PVS) was documented in 26% of the PH cohort, but not associated with increased mortality. ECHO estimation of pulmonary artery pressure (PAP) was available in 84%. PAP was higher in those who died (sPAP/sBP ratio 1.0927 vs 0.8320 %, p=0.0002). At follow-up (mean 250186 weeks PMA), 72% of the PH cohort was alive. Most survivors (66%) had resolution of their PH on their most recent ECHO; 31% remained on PH therapy.CONCLUSION: PH resolved in most survivors in this study population. Mortality in those with BPD-PH was associated with male sex, post-natal steroid use, and increased severity of PH, but not with PVS.
View details for PubMedID 30617286
Per protocol, our institution obtains echocardiograms immediately after each EMB to rule out procedural complication. We sought to determine the incidence of echocardiogram-detected cardiac perforation and TV injury and to evaluate the utility of routine screening echocardiogram after each EMB in the current era. At a single center, 99% (1917/1942) EMB performed in 162 patients were immediately followed by an echocardiogram per protocol. There were five newly diagnosed pericardial effusions, and only one required pericardiocentesis. In the three echocardiograms demonstrating new flail TV, only one patient underwent surgical repair 2months later. This study demonstrates the very low incidence of significant hemopericardium and TV injury after EMB in pediatric heart transplant recipients and argues against the utility of post-EMB echocardiograms to screen solely for procedural complications.
View details for PubMedID 30076684
Right ventricular (RV) function as assessed by deformation has been evaluated prenatally and after palliation in hypoplastic left heart syndrome (HLHS). However, limited data exist about the immediate postnatal cardiac adaptation and RV function in HLHS. We compared echocardiographic measures of cardiac performance in HLHS versus controls in their first week of life. As a secondary objective, we evaluated if markers at the first echocardiogram were associated with mid- and long-term outcomes. Clinical and echocardiographic data of patients with HLHS between 2013 and 2016 were reviewed. The study population was matched with controls whose echocardiograms were obtained due to murmur or rule out coarctation. Speckle-tracking echocardiography was used to assess deformation. Thirty-four patients with HLHS and 28 controls were analyzed. Age at echocardiogram was similar between HLHS and controls. The RV of HLHS was compared to both RV and left ventricle (LV) of controls. HLHS deformation parameters [RV peak global longitudinal strain (GLS), global longitudinal strain rate (GLSR)] and tricuspid annular plane systolic excursion (TAPSE) were decreased compared to RV of controls. The LV-fractional area change, peak GLS, GLSR, circumferential strain, and strain rate of controls were higher than the RV of HLHS. Calculated cardiac output (CO) was higher in the HLHS group (592 vs. 183mL/kg/min, p=0.0001) but similar to the combined LV and RV output of controls. Later mortality or cardiac transplantation was associated with the RV CO and RV stroke distance at initial echocardiogram. Cox proportional hazard regression determined that restriction at atrial septum, decreased initial RV stroke distance and decreased TAPSE had a higher risk of death or cardiac transplantation. TAPSE and RV stroke distance by velocity time integral had adequate inter-reader variability by Bland-Altman plot and Pearson's correlation. Our study found that the HLHS RV deformation is decreased in the early postnatal period when compared to both LV and RV of controls, but deformation was not associated with mid- and long-term outcomes. Later mortality or cardiac transplantation was associated with decreased initial stroke distance and cardiac output. Early evaluation of patients with HLHS should include an assessment of stroke distance and future research should evaluate its implication in management strategies.
View details for PubMedID 30178190
Newborns with congenital diaphragmatic hernia (CDH) have varying degrees of pulmonary hypoplasia and pulmonary hypertension (PH), and there is limited evidence that cardiac dysfunction is present. We sought to study early neonatal biventricular function and performance in these patients by reviewing early post-natal echocardiography (ECHO) measurements and comparing them to normal term newborns.Retrospective case-control study reviewing clinical and ECHO data on term newborns with CDH and normal controls born between 2009 and 2016. Patients were excluded if major anomalies, genetic syndromes, or no ECHO available. PH was assessed by ductal shunting and tricuspid regurgitant jet velocity. Speckle-tracking echocardiography was used to assess myocardial deformation using velocity vector imaging.Forty-four patients with CDH and 18 age-matched controls were analyzed. Pulmonary pressures were significantly higher in the CDH cohort (systolic pulmonary arterial pressure to systolic blood pressure of 10313 vs. 7829%, p=0.0001). CDH patients had decreased RV fractional area change (FAC -28.611.1 vs. 36.29.6%, p=0.02), tricuspid annular plane of systolic excursion (TAPSE-5.61.6 vs. 8.61.6mm, p=0.0001), and RV outflow tract stroke distance (8.62.7 vs. 14.04.5cm, p=0.0001) compared with controls. The left ventricular (LV) ejection fraction was similar in both groups, but CDH patients had a decreased LV end-diastolic volume by Simpson's rule (2.71.0 vs. 5.01.8mL, p=0.0001) and LVOT stroke distance (9.73.4 vs. 12.63.6cm, p=0.004). Biventricular global longitudinal strain (GLS) was markedly decreased in the CDH population compared to controls (RV-GLS: -9.05.3 vs. -19.51.4%, p=0.0001; LV GLS: -13.25.8 vs. -20.83.5%, p=0.0001).CDH newborns have evidence of biventricular dysfunction and decreased cardiac output. Abnormal function may be a factor in the non-response to pulmonary arterial vasodilators in CDH patients. A two-pronged management strategy aimed at improving cardiac function, as well as reducing pulmonary artery pressure in CDH newborns, may be warranted.
View details for PubMedID 29523920
Previous studies have suggested reduced pulmonary valve annulus (PVA) growth and progression of pulmonary outflow obstruction in fetuses with tetralogy of Fallot (TOF). The goals of this study were to (1) investigate the trajectory of PVA growth in utero, and (2) compare two methods of z-score determination for fetal and postnatal PVA size by echocardiography in order to improve prenatal counseling for patients with TOF. Fetal echocardiograms (FE) at a single institution with a diagnosis of TOF between 8/2008 and 12/2015 were retrospectively reviewed. Patients included had at least 2 FEs and 1 immediate postnatal echocardiogram (TTE). Fetal and postnatal demographic, clinical, and echocardiographic data were collected. Fetal body surface area (BSA) was calculated by estimating fetal weight and height; z-scores were determined based on fetal gestational age (GA) and BSA for both FEs and TTEs. Fetal PVA z-scores by GA or BSA were then compared to postnatal PVA z-scores by BSA. Twenty-two patients with 44 FEs and 22 TTEs were included. GA at the first FE was 23weeks3.4 and 32weeks3.1 at the second FE. There was no difference in PVA z-scores (by BSA) between the first and second FE (p=0.34), but a decrease in PVA z-scores (by BSA) between the second FE and TTE (-1.60.5 vs. -2.00.7; p=0.01). Repeat comparison with fetal PVA z-scores indexed to GA revealed no difference in z-scores between the first and second FE, but an increase in PVA z-scores between the second FE (by GA) and TTE (by BSA) (-4.11.0 vs. -2.00.7; p<0.0001). The rate of PVA growth between the two FEs (23m/day9.8) and between the second FE and TTE (28m/day42) remained comparable (p=0.57); however, the rate of BSA increase was greater in later gestation (9cm2/day3 vs. 20 cm2/day11; p=0.001). In patients with TOF, the rate of PVA growth appears to remain consistent through gestation; however, somatic growth rate increases in late gestation. Fetal PVA z-scores indexed to GA are thus inaccurate in predicting postnatal PVA z-scores typically indexed to BSA. This observation should be considered during prenatal consultation and delivery planning.
View details for PubMedID 29632959
For neonates with congenital heart disease (CHD), left-sided (LL) and right-sided (RL) single ventricular physiologies (LL, hypoplastic left heart syndrome; RL, tricuspid atresia or pulmonary atresia with intact ventricular septum) may demonstrate distinct changes in tissue saturation in the first 72 h of life. Near-infrared spectroscopy (NIRS) can measure regional cerebral saturation (Csat) and renal saturation (Rsat) to clarify differences between LL and RL over time.Our primary objective was to measure changes in Csat and Rsat in the first 72 h of life using NIRS between CHD infants with LL compared to RL. The secondary objective was to correlate NIRS values to an echocardiographic marker of perfusion.Newborns with hypoplastic left heart syndrome, tricuspid atresia, and pulmonary atresia with intact ventricular septum from 2013 to 2016 underwent routine NIRS monitoring. Csat, Rsat, and systemic saturations (SpO2) in the first 72 h of life were retrospectively analyzed and the echocardiographic descending aorta velocity time integral (VTI) was measured. Mixed effects models compared differences over time between LL and RL.The final cohort included 13 LL, 12 RL, and 4 controls. Csat decreased for RL compared to LL (p = 0.005), while Rsat decreased for both (p = 0.008). Over time, SpO2 increased for LL but decreased for RL (p = 0.046). Compared to the controls, infants with CHD had lower Csat, lower Rsat, and lower SpO2. The descending aorta VTI was correlated with Rsat (R2 = 0.24, p = 0.02).NIRS Csat measures were better preserved in LL compared to RL. Rsat decreased in both groups through time. The correlation between the descending aorta VTI and Rsat suggests an association between NIRS measures of renal saturation and renal perfusion.
View details for PubMedID 29649824
View details for Web of Science ID 000422946900439
OBJECTIVE: To compare echocardiography (ECHO) findings of patients with congenital diaphragmatic hernia (CDH) who required extracorporeal membrane oxygenation (ECMO) to non-ECMO treated patients.STUDY DESIGN: We reviewed clinical and ECHO data of newborns with CDH born between 2009 and 2016. Exclusions included major anomalies, genetic syndromes, or no ECHO prior to ECMO. Pulmonary hypertension was assessed by ductal shunting and tricuspid regurgitant jet. Speckle tracking echocardiography (STE) assessed function by quantifying deformation.RESULTS: Patients with CDH (15 ECMO and 29 with no ECMO) were analyzed. Most patients had a left CDH (88.6%). Age at ECHO was similar between groups. Outborn status (P=.009) and liver position (P=.009) were associated with need for ECMO. Compared with non-ECMO patients, patients who required ECMO had significantly decreased left and right ventricular function by both conventional and STE measures, as well as decreased right and left ventricular output. The right ventricular eccentricity index was higher in ECMO vs non-ECMO patients (2.2 vs 1.8, P=.02). There was no difference in pulmonary hypertension between CDH groups.CONCLUSIONS: Need for ECMO was associated with decreased left and right ventricular function, as assessed by standard and STE measures. There was no difference in pulmonary hypertension between non ECMO and ECMO patients. Abnormal cardiac function may explain nonresponse to pulmonary vasodilators in patients with CDH. Management strategies to improve cardiac function may reduce the need for ECMO in newborns with CDH.
View details for PubMedID 29037794
Congenitally corrected transposition of the great arteries is a rare form of congenital heart disease.Management is controversial; options include observation, physiologic repair, and anatomic repair. Assessment of morphologic left ventricle preparedness is key in timing anatomic repair. This study's purpose was to review the modalities used to assess the morphologic left ventricle preoperatively and to determine ifany echocardiographic variables are associated with outcomes.A retrospective review of patients with congenitally corrected transposition of the great arteries eligible for anatomic repair at Lucile Packard Children's Hospital from 2000 to 2016 was conducted. Inclusion criteria were (1) presurgical echocardiography, magnetic resonance imaging, and cardiac catheterization and (2) clinical follow-up information. Echocardiographic measurements included left ventricular (LV) single-plane Simpson's ejection fraction, LV eccentricity index, LV posterior wall thickening, pulmonary artery band (PAB)/LV outflow tract (LVOT) pressure gradient, and LV and right ventricular strain. Magnetic resonance imaging measurements included LV mass, ejection fraction, eccentricity index, and LV thickening. LV pressure, PAB/LVOT gradient, right ventricular pressure, pulmonary vascular resistance, and Qp/Qs constituted catheterization data. Outcomes included achieving anatomic repair within 1year of assessment in patients with LVOT obstruction or within 1year of pulmonary artery banding and freedom from death, transplantation, or heart failure at last follow-up.Forty-one patients met the inclusion criteria. PAB/LVOT gradients of 85.223.4 versus 64.032.1mmHg (P=.0282) by echocardiography and 60.119.4 versus 35.918.9mmHg (P=.0030) by catheterization were associated with achieving anatomic repair and freedom from death, transplantation, and heart failure. Echocardiographic LV posterior wall thickening of 35.419.8% versus 20.615.0% (P=.0017) and MRI LV septal wall thickening of 37.118.8% versus 19.318.8% (P=.0306) were associated with achieving anatomic repair. Inter- and intraobserver variability for echocardiographic measurements was very good.PAB/LVOT gradient and LV posterior wall thickening are highly reproducible echocardiographic measurements that reflect morphologic LV performance and can be used in assessing patients with congenitally corrected transposition of the great arteries undergoing anatomic repair.
View details for DOI 10.1016/j.echo.2017.03.019
View details for PubMedID 28579248
Left ventricular outflow tract velocity time integral (LVOT-VTI), a Doppler-derived measure of stroke distance, is used as a surrogate marker of cardiac function in adults. LVOT-VTI is easily obtained, independent of ventricular geometry and wall motion abnormalities. We investigated the relationship between LVOT-VTI and conventional measures of function in young patients by comparing controls to children with dilated cardiomyopathy (DCM). Sixty-two healthy and 52 DCM patients over 1year were studied retrospectively. The average pulsed (PW) and continuous wave (CW) LVOT-VTIs from apical views were measured from three cycles. Body surface area (BSA) and Ejection fraction (EF) were obtained. We compared LVOT-VTIs between study and control groups and assessed BSA's impact on LVOT-VTI. The entire cohort was classified into three levels of LV function which were compared. We determined LVOT-VTI cutoff values that indicated an EF<50%. The mean PW-LVOT-VTI in the DCM group was significantly lower than that of the normal group (0.15 vs. 0.18m; p<0.0012). The mean CW-LVOT-VTI was significantly lower in DCM (0.20 vs. 0.24m; p<0.0001). There was no impact of BSA on LVOT-VTI except when comparing BSA and CW-LVOT-VTI in the normal group. There was a positive relationship between LVOT-VTI and EF for PW (Rs=0.29, p=0.0022) and CW (Rs=0.22, p=0.0364) and a difference in mean LVOT-VTI between EF groups (p<0.0001). ROC analysis demonstrated that PW-LVOT-VTI<0.17m (AUC=0.73; p<0.0001) and CW-LVOT-VTI<0.22m (AUC=0.76; p<0.0001) was associated with EF<50%. This study indicates that LVOT-VTI can be a useful alternative measure of LV performance in children over 1year.
View details for DOI 10.1007/s00246-017-1630-9
View details for PubMedID 28534242
Major aortopulmonary collateral arteries (MAPCAs) are frequently found in association with pulmonary atresia with ventricular septal defect (PA/VSD). However, some patients with MAPCAs do not have PA/VSD but have a variety of other "atypical" anatomic diagnoses.This was a retrospective review of patients with MAPCAs and atypical anatomy. The 50 patients with MAPCAs could be divided into two subgroups: (1) single ventricle anatomy (n= 33) and (2) two ventricle anatomy (n= 17).The 33 patients with MAPCAs and single ventricle included 15 with unbalanced complete atrioventricular canal (CAVC), 6 with pulmonary atresia-intact ventricular septum, and 12 with other forms of single ventricle. The initial cardiac operation included unifocalization/shunt in 24 patients and creation of aortopulmonary window or central shunt in 9 patients. There were seven operative and eight late deaths. Sixteen patients have had a bidirectional Glenn procedure and6 had a Fontan procedure. The 17 patients with MAPCAs and two ventricles included 5 with CAVC, 4 with corrected transposition, 3 with double outlet right ventricle, 3 with scimitar syndrome, and 2 with complex D-transposition. The initial cardiac operation included single-stage complete repair in 5 patients, unifocalization/shunt in 10 patients, and aortopulmonary window in 2 patients. There were two operative and two late deaths. Thirteen patients have achieved complete repair status.The data demonstrate the wide diversity of anatomy seen in patients with MAPCAs when evaluating diagnoses other than PA/VSD. Two-thirds of the patients had single ventricle and was associated with a relatively high mortality.
View details for DOI 10.1016/j.athoracsur.2017.02.029
View details for PubMedID 28527961
The effect of veno-arterial extracorporeal membrane oxygenation (VA ECMO) on wall stress in patients with cardiomyopathy, myocarditis, or other cardiac conditions is unknown. We set out to determine the circumferential and meridional wall stress (WS) in patients with systemic left ventricles before and during VA ECMO. We established a cohort of patients with impaired myocardial function who underwent VA ECMO therapy from January 2000 to November 2013. Demographic and clinical data were collected and inotropic score calculated. Measurements were taken on echocardiograms prior to the initiation of VA ECMO and while on full-flow VA ECMO, in order to derive wall stress (circumferential and meridional), VCFc, ejection fraction, and fractional shortening. A post hoc sub-analysis was conducted, separating those with pulmonary hypertension (PH) and those with impaired systemic output. Thirty-three patients met inclusion criteria. The patients' median age was 0.06years (range 0-18.7). Eleven (33%) patients constituted the organ failure group (Gr2), while the remaining 22 (66%) patients survived to discharge (Gr1). WS and all other echocardiographic measures were not different when comparing patients before and during VA ECMO. Ejection and shortening fraction, WS, and VCFc were not statistically different comparing the survival and organ failure groups. The patients' position on the VCFc-WS curve did not change after the initiation of VA ECMO. Those with PH had decreased WS as well as increased EF after ECMO initiation, while those with impaired systemic output showed no difference in those parameters with initiation of ECMO. The external workload on the myocardium as indicated by WS is unchanged by the institution of VA ECMO support. Furthermore, echocardiographic measures of cardiac function do not reflect the changes in ventricular performance inherent to VA ECMO support. These findings are informative for the interpretation of echocardiograms in the setting of VA ECMO. ECMO may improve ventricular mechanics in those with PH as the primary diagnosis.
View details for DOI 10.1007/s00246-016-1546-9
View details for Web of Science ID 000398030200013
Pulmonary hypertension (PH) is associated with bronchopulmonary dysplasia (BPD). Screening strategies, a thorough investigation of co-morbidities, and multidisciplinary involvement prior to anti-PH medications have been advocated by recent guidelines. We sought to evaluate current practices of neonatologists caring for premature infants with PH.Electronic survey of American Academy of Pediatrics neonatology members.Among 306 neonatologist respondents, 38% had an institutional screening protocol for patients with BPD; 83% screened at 36 weeks for premature neonates on oxygen/mechanical ventilation. In those practicing more than 5 years, 54% noted increasing numbers of premature infants diagnosed with PH. Evaluation for PH in BPD patients included evaluations for micro-aspiration (41%), airways anomalies (29%), and catheterization (10%). Some degree of acquired pulmonary vein stenosis was encountered in 47%. A majority (90%) utilized anti-PH medications during the neonatal hospitalization.Screening for PH in BPD, and subsequent evaluation and management is highly variable.
View details for PubMedID 29234146
The effect of veno-arterial extracorporeal membrane oxygenation (VA ECMO) on wall stress in patients with cardiomyopathy, myocarditis, or other cardiac conditions is unknown. We set out to determine the circumferential and meridional wall stress (WS) in patients with systemic left ventricles before and during VA ECMO. We established a cohort of patients with impaired myocardial function who underwent VA ECMO therapy from January 2000 to November 2013. Demographic and clinical data were collected and inotropic score calculated. Measurements were taken on echocardiograms prior to the initiation of VA ECMO and while on full-flow VA ECMO, in order to derive wall stress (circumferential and meridional), VCFc, ejection fraction, and fractional shortening. A post hoc sub-analysis was conducted, separating those with pulmonary hypertension (PH) and those with impaired systemic output. Thirty-three patients met inclusion criteria. The patients' median age was 0.06years (range 0-18.7). Eleven (33%) patients constituted the organ failure group (Gr2), while the remaining 22 (66%) patients survived to discharge (Gr1). WS and all other echocardiographic measures were not different when comparing patients before and during VA ECMO. Ejection and shortening fraction, WS, and VCFc were not statistically different comparing the survival and organ failure groups. The patients' position on the VCFc-WS curve did not change after the initiation of VA ECMO. Those with PH had decreased WS as well as increased EF after ECMO initiation, while those with impaired systemic output showed no difference in those parameters with initiation of ECMO. The external workload on the myocardium as indicated by WS is unchanged by the institution of VA ECMO support. Furthermore, echocardiographic measures of cardiac function do not reflect the changes in ventricular performance inherent to VA ECMO support. These findings are informative for the interpretation of echocardiograms in the setting of VA ECMO. ECMO may improve ventricular mechanics in those with PH as the primary diagnosis.
View details for DOI 10.1007/s00246-016-1546-9
View details for PubMedID 28005156
Present resource-based relative value unit (RVU) assignment for echocardiography is based on Current Procedural Terminology (CPT) codes, which do not incorporate complexity of diagnosis, time spent for image acquisition, or interpretation of echocardiograms. The objective of this study was to determine whether CPT-based RVU assignment accurately reflects physician effort in performing and interpreting pediatric echocardiographic examinations.Cardiac complexity category (CCC) and physician time for study interpretation of 123 echocardiograms (June to September 2013) were prospectively assigned. Categories included (1) focused effusion/function evaluation, (2) normal anatomy/focused preterm infant studies, (3) acquired heart disease, (4) congenital heart disease excluding single ventricles, (5) single ventricles including heterotaxy syndrome, and (6) hearts on mechanical support. Subsequently, a random sample of echocardiograms (March to August 2013) were retrospectively analyzed, and each study was assigned a CCC and an extrapolated median interpretation time (MIT) on the basis of prospective data collection. Assigned work RVUs based on CPT codes were recorded. Comparisons were made between CCC and time for study interpretation, work RVUs, number of images acquired, and total scan time.A total of 933 echocardiograms were analyzed: 198 (21%), 174 (19%), 98 (11%), 359 (35%), 84 (9%), and 20 (2%) studies in CCCs 1 to 6, respectively. Total scan time, MIT, number of images, and work RVUs were different among CCCs (P<.0001). However, among the more complex studies (CCCs 2-5), work RVUs were similar, while number of images obtained and MIT were different (P<.001). Correlation analysis showed no association between work RVUs and CCC, total scan, or number of images per study. Compared with older patients, work RVUs of studies in children <2years of age were lower, while all other markers of study complexity were higher (P<.05).Current CPT-based assignment of work RVUs does not discriminate study complexity and physician effort. The results of this study highlight the need for a refined system that accurately assesses physician effort in pediatric echocardiography.
View details for DOI 10.1016/j.echo.2016.05.015
View details for PubMedID 27405593
Pulmonary valve (PV) insufficiency is often an acquired condition after treatment for pulmonary stenosis. It is recognized that PV insufficiency has serious deleterious effects. Although surgical replacement of the PV is efficacious, artificial valves inevitably fail and require re-intervention. The purpose of this study was to summarize our experience with PV repair in patients with acquired PV insufficiency.This was a retrospective review of 16 patients with marked PV insufficiency who underwent PV repair. Thirteen of these patients were born with tetralogy of Fallot (TOF) and had undergone a previous transannular patch repair. Three patients were born with critical pulmonary stenosis and had a surgical valvotomy or balloon valvuloplasty.The 13 patients with TOF had resection of their previously placed transannular patch with re-approximation of the anterior commissure. All 13 patients experienced a marked reduction in the degree of pulmonary insufficiency. None of these patients have experienced any increase in insufficiency during follow-up. The 3 patients with critical pulmonary stenosis had a variety of pathologic findings identified at the surgical procedure. One patient had a large gap between a commissure and underwent closure of that commissure. The second and third patients had torn leaflets repaired with pericardial and Gore-Tex patches (Gore, Inc, Flagstaff, AZ). The degree of PV insufficiency was decreased to mild in all 3 patients. However, 2 of these 3 patients have subsequently had an increase in the degree of pulmonary insufficiency.Patients with TOF who underwent a previous transannular patch may be candidates for bicuspidization of their native PV, and the results of this procedure have been quite stable at follow-up. PV repair for torn leaflets was effective in the short term but was less stable over time.
View details for DOI 10.1016/j.athoracsur.2016.01.035
View details for Web of Science ID 000376502600043
View details for PubMedID 27083251
Exercise echocardiography is an underutilized tool in pediatrics with current applications including detecting segmental wall abnormalities, assessing the utility of global ventricular function, and measuring pulmonary hemodynamics. No prior study has applied speckle-tracking echocardiography (STE) during exercise echocardiography in children. The aim of this study was to determine the feasibility of measuring speckle-tracking-derived peak systolic velocities, global longitudinal and circumferential strain, and global strain rates at various phases of exercise. Ninety-seven healthy children underwent cardiopulmonary exercise testing using supine cycle ergometry. The exercise stress test consisted of baseline pulmonary function testing, monitoring of blood pressure and heart rate responses, electrocardiographic recordings, and oxygen saturations while subjects pedaled against a ramp protocol based on body weight. Echocardiographic measurements and specifically speckle-tracking analysis were performed during exercise at baseline, at a heart rate of 160 beats per minute and at 10min after exercise. Peak systolic velocity, peak systolic strain, and peak systolic strain rate at these three phases were compared in the subjects in which all measurements were accurately obtained. We were able to complete peak velocity, strain, and strain rate measurements in all three exercise phases for 36 out of the 97 subjects tested. There was no significant difference between the feasibility of measuring circumferential versus longitudinal strain (p=0.25, B-corrected=0.75). In the 36 subjects studied, the magnitude of circumferential strain values decreased from -18.34.8 to -13.74.0% from baseline to HR 160 (p<0.0001, B-corrected<0.0001), before returning to -19.64.4% at recovery (p=0.19 when compared to baseline). Longitudinal strain did not vary significantly from baseline to HR 160 (from -17.74.4 to -16.64.4%, p=0.16); likewise the average recovery strain was no different from those values (-18.43.6%; p=0.34). Peak circumferential and longitudinal strain rates increased from baseline to HR 160, but neither decreased to baseline levels after 10min of recovery, which correlated with heart rate variations with exercise. We studied the effects of frame rate on deformation measurements and we observed no difference between measurements taken at lower (<60 frames per second, fps) and higher (60fps) frame rates. This study shows that it is technically difficult to retrospectively measure peak velocities, strain, and strain rate in exercising pediatric subjects with STE. The majority of subjects that were excluded from the study had inadequate echocardiographic images when tachycardic from increased respiratory effort and body movements near peak exercise. Improvements in technique and higher image frame rates could make application of STE to pediatric cardiopulmonary testing more successful in the future.
View details for DOI 10.1007/s00246-015-1309-z
View details for PubMedID 26671508
Exercise echocardiography is an underutilized tool in pediatrics with current applications including detecting segmental wall abnormalities, assessing the utility of global ventricular function, and measuring pulmonary hemodynamics. No prior study has applied speckle-tracking echocardiography (STE) during exercise echocardiography in children. The aim of this study was to determine the feasibility of measuring speckle-tracking-derived peak systolic velocities, global longitudinal and circumferential strain, and global strain rates at various phases of exercise. Ninety-seven healthy children underwent cardiopulmonary exercise testing using supine cycle ergometry. The exercise stress test consisted of baseline pulmonary function testing, monitoring of blood pressure and heart rate responses, electrocardiographic recordings, and oxygen saturations while subjects pedaled against a ramp protocol based on body weight. Echocardiographic measurements and specifically speckle-tracking analysis were performed during exercise at baseline, at a heart rate of 160 beats per minute and at 10min after exercise. Peak systolic velocity, peak systolic strain, and peak systolic strain rate at these three phases were compared in the subjects in which all measurements were accurately obtained. We were able to complete peak velocity, strain, and strain rate measurements in all three exercise phases for 36 out of the 97 subjects tested. There was no significant difference between the feasibility of measuring circumferential versus longitudinal strain (p=0.25, B-corrected=0.75). In the 36 subjects studied, the magnitude of circumferential strain values decreased from -18.34.8 to -13.74.0% from baseline to HR 160 (p<0.0001, B-corrected<0.0001), before returning to -19.64.4% at recovery (p=0.19 when compared to baseline). Longitudinal strain did not vary significantly from baseline to HR 160 (from -17.74.4 to -16.64.4%, p=0.16); likewise the average recovery strain was no different from those values (-18.43.6%; p=0.34). Peak circumferential and longitudinal strain rates increased from baseline to HR 160, but neither decreased to baseline levels after 10min of recovery, which correlated with heart rate variations with exercise. We studied the effects of frame rate on deformation measurements and we observed no difference between measurements taken at lower (<60 frames per second, fps) and higher (60fps) frame rates. This study shows that it is technically difficult to retrospectively measure peak velocities, strain, and strain rate in exercising pediatric subjects with STE. The majority of subjects that were excluded from the study had inadequate echocardiographic images when tachycardic from increased respiratory effort and body movements near peak exercise. Improvements in technique and higher image frame rates could make application of STE to pediatric cardiopulmonary testing more successful in the future.
View details for DOI 10.1007/s00246-015-1309-z
View details for Web of Science ID 000373308800012
Abnormalities in coronary artery (CA) flow detected by echocardiography are increasingly used to guide clinical decisions in patient management. Increased CA flow has been seen postoperatively in congenital cardiac surgery. This study sought to determine immediate postoperative changes in left anterior descending (LAD) CA flow velocities, and to investigate possible factors associated with these changes. CA flow in the proximal LAD was sampled with pulsed-wave Doppler during trans-esophageal echocardiography imaging in the immediate preoperative and postoperative studies in 46 subjects. The peak velocity, velocity time integral (VTI), VTI corrected for heart rate (VTIc), and VTI rate pressure product (VTIrpp) were determined. The percent change in each measure between the preoperative and postoperative study was calculated and compared to age, body surface area (BSA), cardiopulmonary bypass time, cross-clamp time, and number of cardioplegia (CP) doses. The pH, oxygen saturation, temperature, and hemoglobin concentration (Hb) were compared for those with and without increased flow characteristics. There was an overall increase in LAD flow parameters in subjects who underwent congenital cardiac surgery. There was a significant and positive correlation of percent change in VTI, VTIc, and VTIrrp with number of CP doses and lower Hb. We propose that this phenomenon is likely of multifactorial origin, involving autoregulatory mechanism disturbance. The imaging and measurement of LAD flow velocities are feasible, reliable, and is positively correlated with number of CP doses. Interpretation of postoperative LAD flow velocities should be made in the context of intraoperative events since heart rate, blood pressure, and Hb concentration also influence CA flow parameters.
View details for DOI 10.1007/s00246-015-1285-3
View details for PubMedID 26481223
There are conflicting reports regarding the importance of mitral stenosis and aortic atresia as a risk factor for Norwood mortality. This study reviews outcomes of this anatomic subgroup at our institution and examines the utility of preoperative cardiac catheterization and its correlation with clinical outcomes and pathology findings.This is a single-center, retrospective review of hypoplastic left heart syndrome patients who underwent modified Norwood operation between October 2005 and May2013.Fourteen of 74 hypoplastic left heart syndrome patients (19%) had mitral stenosis and aortic atresia. Operative mortality for MS/AA was 29% versus 7% for all other hypoplastic left heart syndrome anatomic subgroups (p= 0.04). Although only 19% of the entire cohort, the mitral stenosis and aortic atresia subgroup constituted 50% of the total operative mortality and the only interstage deaths. Autopsies support myocardial ischemia as the mechanism of death. Although preoperative angiography defined the presence of ventriculo-coronary connections, it did not clearly risk stratify patients in regard to operative mortality.Mitral stenosis and aortic atresia is a risk factor for perioperative myocardial ischemia and mortality. Further exploration of myocardial reserve is warranted.
View details for DOI 10.1016/j.athoracsur.2015.09.056
View details for Web of Science ID 000368184300032
There are conflicting reports regarding the importance of mitral stenosis and aortic atresia as a risk factor for Norwood mortality. This study reviews outcomes of this anatomic subgroup at our institution and examines the utility of preoperative cardiac catheterization and its correlation with clinical outcomes and pathology findings.This is a single-center, retrospective review of hypoplastic left heart syndrome patients who underwent modified Norwood operation between October 2005 and May2013.Fourteen of 74 hypoplastic left heart syndrome patients (19%) had mitral stenosis and aortic atresia. Operative mortality for MS/AA was 29% versus 7% for all other hypoplastic left heart syndrome anatomic subgroups (p= 0.04). Although only 19% of the entire cohort, the mitral stenosis and aortic atresia subgroup constituted 50% of the total operative mortality and the only interstage deaths. Autopsies support myocardial ischemia as the mechanism of death. Although preoperative angiography defined the presence of ventriculo-coronary connections, it did not clearly risk stratify patients in regard to operative mortality.Mitral stenosis and aortic atresia is a risk factor for perioperative myocardial ischemia and mortality. Further exploration of myocardial reserve is warranted.
View details for DOI 10.1016/j.athoracsur.2015.09.056
View details for PubMedID 26602002
The assessment of left ventricular (LV) systolic function using conventional echocardiographic measures is problematic in the setting of mitral regurgitation (MR) given that altered loading conditions can mask underlying ventricular dysfunction. The purpose of this study was to characterize LV function and deformation before and after effective mitral valve repair or replacement to determine echocardiographic measures associated with early postoperative myocardial dysfunction.Baseline LV function was assessed retrospectively by conventional echocardiography and speckle-tracking strain analysis pre- and postoperatively in patients diagnosed with MR between January 2000 and March 2013, excluding patients with less than mild to moderate MR preoperatively, left-sided obstructive lesions, large septal defects, or more than mild MR postoperatively.Forty-six pediatric patients were evaluated (average age, 8.26.4years). Thirteen patients had normal preoperative ejection fractions but significant postoperative dysfunction (defined as an ejection fraction < 50%). Compared with the 33 patients with normal postoperative function, age (11.57.1 vs 7.35.7 years, P=.04), global circumferential strain (-13.25.6% vs -17.14.6%, P=.02), and global circumferential strain rate (-0.940.40 vs -1.360.42 sec(-1), P=.004) were found to be statistically different. Using receiver operating characteristic curves, an older preoperative age (area under the curve, 0.67; P=.03), lower global circumferential strain magnitude (area under the curve, 0.74; P=.007), and lower global circumferential strain rate magnitude (area under the curve, 0.80; P=.0004) were determined to be factors associated with early postoperative LV dysfunction after surgical repair of MR.Strain measurements may be useful as part of the echocardiographic assessment of patients with MR and can guide timing for surgical repair in the pediatric population.
View details for DOI 10.1016/j.echo.2014.11.010
View details for PubMedID 25555521
The assessment of left ventricular (LV) systolic function using conventional echocardiographic measures is problematic in the setting of mitral regurgitation (MR) given that altered loading conditions can mask underlying ventricular dysfunction. The purpose of this study was to characterize LV function and deformation before and after effective mitral valve repair or replacement to determine echocardiographic measures associated with early postoperative myocardial dysfunction.Baseline LV function was assessed retrospectively by conventional echocardiography and speckle-tracking strain analysis pre- and postoperatively in patients diagnosed with MR between January 2000 and March 2013, excluding patients with less than mild to moderate MR preoperatively, left-sided obstructive lesions, large septal defects, or more than mild MR postoperatively.Forty-six pediatric patients were evaluated (average age, 8.26.4years). Thirteen patients had normal preoperative ejection fractions but significant postoperative dysfunction (defined as an ejection fraction < 50%). Compared with the 33 patients with normal postoperative function, age (11.57.1 vs 7.35.7 years, P=.04), global circumferential strain (-13.25.6% vs -17.14.6%, P=.02), and global circumferential strain rate (-0.940.40 vs -1.360.42 sec(-1), P=.004) were found to be statistically different. Using receiver operating characteristic curves, an older preoperative age (area under the curve, 0.67; P=.03), lower global circumferential strain magnitude (area under the curve, 0.74; P=.007), and lower global circumferential strain rate magnitude (area under the curve, 0.80; P=.0004) were determined to be factors associated with early postoperative LV dysfunction after surgical repair of MR.Strain measurements may be useful as part of the echocardiographic assessment of patients with MR and can guide timing for surgical repair in the pediatric population.
View details for DOI 10.1016/j.echo.2014.11.010
View details for Web of Science ID 000352144400004
View details for PubMedID 25555521
This is the first report of the use of veno-venous extracorporeal membrane oxygenation in a neonate with severe Ebstein's anomaly. The report suggests the use of veno-venous extracorporeal membrane oxygenation in the immediate neonatal period may be a useful therapy in severe Ebstein's anomaly. By providing adequate oxygenation independent of the patient's native pulmonary blood flow, veno-venous extracorporeal membrane oxygenation allows the pulmonary vascular resistance to decrease and may promote right ventricular recovery.
View details for DOI 10.4103/0974-2069.149527
View details for PubMedID 25684893
View details for PubMedCentralID PMC4322407
Currently, there are no established echocardiographic or hemodynamic predictors of mortality after weaning venoarterial extracorporeal membrane oxygenation in children. We wished to determine which measurements predict mortality.Over 3 years, we prospectively assessed six echo and six hemodynamic variables at 3-5 circuit rates while weaning extracorporeal membrane oxygenation flow. Hemodynamic measurements were heart rate, inotropic score, arteriovenous oxygen difference, pulse pressure, oxygenation index, and lactate. Echo variables included shortening/ejection fraction, outflow tract Doppler-derived stroke distance (velocity-time integral), degree of atrioventricular valve regurgitation, longitudinal strain (global longitudinal strain), and circumferential strain (global circumferential strain).Cardiovascular ICU at Lucille Packard Children's Hospital Stanford, CA.Patients were stratified into those who died or required heart transplant (Gr1) and those who did not (Gr2). For each patient, we compared the change for each variable between full versus minimum extracorporeal membrane oxygenation flow for each group.None.We enrolled 21 patients ranging in age from 0.02 to 15 years. Five had dilated cardiomyopathy, and 16 had structural heart disease with severe ventricular dysfunction. Thirteen of 21 patients (62%) comprised Gr1, including two patients with heart transplants. Eight patients constituted Gr2. Gr1 patients had a significantly greater increase in oxygenation index (35% mean increase; p < 0.01) off extracorporeal membrane oxygenation compared to full flow, but no change in velocity-time integral or arteriovenous oxygen difference. In Gr2, velocity-time integral increased (31% mean increase; p < 0.01), with no change in arteriovenous oxygen difference or oxygenation index. Pulse pressure increased modestly with flow reduction only in Gr1 (p < 0.01).Failure to augment velocity-time integral or an increase in oxygenation index during the extracorporeal membrane oxygenation weaning is associated with poor outcomes in children. We propose that these measurements should be performed during extracorporeal membrane oxygenation wean, as they may discriminate who will require alternative methods of circulatory support for survival.
View details for DOI 10.1097/PCC.0000000000000236
View details for PubMedID 25230312
In tetralogy of Fallot with absent pulmonary valve, pulmonary stenosis and regurgitation results in significant pulmonary artery dilatation. Branch pulmonary artery dilatation often compresses the tracheobronchial tree, causing fluid trapping in fetal life and air trapping and/or atelectasis after birth. Prenatal diagnosis predicts poor prognosis, which depends on the degree of respiratory insufficiency from airway compromise and lung parenchymal disease after birth. Fetal magnetic resonance imaging (MRI) has been useful in evaluating the effects of congenital lung lesions on lung development and indicating severity of pulmonary hypoplasia. This report is the first demonstrating the utility of fetal MRI in tetralogy of Fallot/absent pulmonary valve patients, which predicted postnatal pulmonary artery size and visualized airway compression and lung parenchymal lesions. The distribution of lobar fluid trapping on fetal MRI correlated with air trapping on postnatal computed tomography angiogram.
View details for DOI 10.1111/chd.12091
View details for PubMedID 23701739
View details for DOI 10.1111/chd.12091
View details for PubMedID 23701739
View details for DOI 10.1016/S0735-1097(14)60485-X
View details for Web of Science ID 000359579101143
Advances in fetal cardiac imaging have resulted in changes in the practice of fetal cardiology, and in improved neonatal outcomes for these patients. As the anatomic diagnostic accuracy of fetal cardiology has improved, cardiologists have sought new challenges in fetal imaging, and with new emphasis on improved front line detection, treatment/intervention during fetal life, and assessment of fetal ventricular function and cardiovascular performance. The evolution of noninvasive assessment of fetal cardiac function is related to technologic advances in ultrasound imaging. This article reviews conventional methods of the assessment of cardiac function, as well as some promising directions for future evaluation with emphasis on future applications of 3D echocardiography and 3D speckle tracking echocardiography.
View details for PubMedID 29637504
In chronic aortic insufficiency (AI), left-ventricular (LV) dysfunction must be detected early to allow timely surgery. Strain and strain rate have been used for this purpose in adults, but the value of this method in pediatric AI has not been established. Forty patients with moderate to severe AI were included in this retrospective study. LV function was assessed by strain analysis and conventional echocardiography both before and after surgery. Of the 32 patients with preserved preoperative ejection fraction (EF; >50%), 8 had postoperative dysfunction (<50%). Mean conventional indices of global LV systolic performance for the entire cohort of patients with AI were predominantly in the normal range before surgery. Preoperative values for LV global longitudinal strain (GLS) and strain rate (GLSr) were normal. After surgery, there was a significant decrease in shortening and EF. There was a significant decrease from preoperative to postoperative values for both GLS (-16.073.82 vs. -11.063.88; p<0.0001) and GLSr (-0.890.24 vs. -0.720.27; p=0.0021). A preoperative GLS of -15.3 (AUC=0.83, CI=0.69-0.98, p<0.0001) and a GLSr of -0.79/s (AUC=0.86, CI=0.73-0.98, p<0.0001) were determined to be predictors of early postoperative dysfunction after surgical repair of moderate to severe AI. A preoperative GLS value of -15.3 and GLSr value of -0.79/s or less are predictors of postoperative ventricular dysfunction, which is defined by EF <50%. GLS and GLSr value determination may be useful as part of the echocardiographic assessment AI and may help determine the optimal timing of surgery in pediatric patient with at least moderate AI.
View details for DOI 10.1007/s00246-013-0646-z
View details for Web of Science ID 000321919400006
View details for PubMedID 23389100
We report a unique case of tricuspid and pulmonary atresia with idiopathic progressive ductus arteriosus restriction in utero. Diligent predelivery planning and a controlled delivery environment led to a favorable outcome.
View details for DOI 10.1007/s00246-012-0391-8
View details for Web of Science ID 000321919400028
We report a unique case of tricuspid and pulmonary atresia with idiopathic progressive ductus arteriosus restriction in utero. Diligent predelivery planning and a controlled delivery environment led to a favorable outcome.
View details for DOI 10.1007/s00246-012-0391-8
View details for PubMedID 22729970
BACKGROUND: Patients with ventriculoarterial discordance, such as congenitally corrected and d-transposition of the great arteries, may undergo a morphologic left ventricular (LV) training strategy consisting of surgical pulmonary artery band (PAB) placement and subsequent anatomic repair to establish ventriculoarterial concordance. The purpose of this study was to characterize morphologic LV function and deformation longitudinally using speckle-tracking strain analysis in patients with ventriculoarterial discordance who underwent LV training. METHODS: Twenty-nine patients (12 with d-transposition of the great arteries and 17 with congenitally corrected transposition of the great arteries) who underwent LV training with PAB placement were evaluated retrospectively. LV ejection fraction and global and regional longitudinal strain and strain rate were measured before and 7 5 days after PAB placement and subsequent anatomic repair. RESULTS: PAB placement caused reductions in the mean LV ejection fraction from 76.1 10.2% to 66.7 7.8% (P < .001), in mean global strain from -17.7 9% to -13.3 7.5% (P= .01), and in mean lateral wall strain from -23.3 12.8% to -17.5 10.3% (P= .01). After anatomic repair (a median of 21 months after PAB placement; range, 0.5-104 months), mean LV ejection fraction decreased further from 63.3 8.6% to 52.4 14.9% (P < .05). Mean global strain declined from -17.6% 4.4 to -12.6 4% (P= .01), and mean lateral wall strain decreased from -18.2 11.4% to -12.6 5.3% (P= .04). CONCLUSIONS: In patients with ventriculoarterial discordance undergoing PAB placement for LV training and anatomic repair, the morphologic left ventricle demonstrated decremental systolic function and global longitudinal deformation acutely. Frequent functional assessment is warranted to understand long-term myocardial mechanics in these patients.
View details for DOI 10.1016/j.echo.2013.03.017
View details for Web of Science ID 000321051000011
View details for PubMedID 23623593
We describe a newborn with a phenotype consistent with Adams-Oliver syndrome and truncus arteriosus. Although cardiovascular malformations associated with this syndrome have been previously published in the literature, this is the first description of truncus arteriosus in a patient with Adams-Oliver syndrome. We review other reports of Adams-Oliver syndrome previously described with cardiovascular malformations, consider possible genetic and embryologic mechanisms, and emphasize the need for cardiology consultation when a diagnosis of Adams-Oliver syndrome is suspected in the differential diagnosis. 2013 Wiley Periodicals, Inc.
View details for DOI 10.1002/ajmg.a.35864
View details for Web of Science ID 000320649700021
To determine the prevalence of congenital heart defects (CHDs) in a large, unselected cohort of monochorionic (MC) twins.We completed a chart review of all MC twin pregnancies in the Kaiser Permanente Northern California population from 1996 to 2003. CHDs were identified by diagnostic codes and confirmed by postnatal echocardiograms. Follow-up was obtained through one year of age.A total of 926 liveborn MC twins met inclusion criteria. The prevalence of CHDs was 7.5%, 11.6 times the general population rate (CI 9.2 to 14.5). Septal defects were most common. 20% of infants with heart defects had twin-to-twin transfusion syndrome (TTTS) versus 8% of infants without defects (P<0.01); this association remained significant when controlling for potential confounders.The prevalence of CHDs in this large cohort of MC twins was significantly higher than the general population rate, with TTTS an added risk factor.
View details for DOI 10.1038/jp.2012.145
View details for Web of Science ID 000319657300008
View details for PubMedID 23223160
In postnatal life, patients with single ventricle (SV) with morphologic right ventricles have a worse prognosis than those with morphologic left ventricles. The aim of this study was to test the hypotheses that (1) the SV in fetuses with SV has decreased longitudinal strain compared with fetuses with normal cardiac anatomy, and (2) fetuses with SV right ventricular (RV) morphology have decreased strain compared with those with SV left ventricular (LV) morphology.Fetal echocardiograms with SV RV and SV LV morphology were retrospectively compiled. Postprocessing analysis of the dominant ventricle was done using syngo Velocity Vector Imaging version 2.0. Peak global longitudinal strain (GLS) and global longitudinal strain rate (GL SR) were generated. Both the right and left ventricles were analyzed in fetuses with normal cardiac anatomy for comparison.Fifty-four fetuses with SV (18 with LV morphology and 36 with RV morphology) were included in the study and compared with 54 controls matched for gestational age. Global longitudinal strain and GL SR were compared between fetuses with SV and normal fetuses and among SV subsets. When all four categories were compared (normal left ventricle, normal right ventricle, SV left ventricle, and SV right ventricle), there was no difference in GLS (P = .49) or in GL SR (P = .32) between any of the categories.Comparable GLS and GL SR values between fetal SV of LV or RV morphology, as well as normal fetal left and right ventricles, reflect in utero preservation of systolic function of the SV heart.
View details for DOI 10.1016/j.echo.2012.10.007
View details for Web of Science ID 000313012600010
View details for PubMedID 23140844
We sought to evaluate the completeness of echocardiographic diagnosis of fetal tetralogy of Fallot (fTOF) at 12-17 weeks gestation, and compare assessment and clinical outcomes to diagnoses made at >17 weeks gestation.We identified all fTOF diagnoses made in our experience from 2003 to 2008. Referral indication, anatomic detail by echocardiography and pregnancy outcomes were compared between fetuses diagnosed at 17 weeks (Group I) and >17 weeks gestation (Group II). A 10-point scoring tool was applied retrospectively to the echocardiograms at initial diagnosis (1 point each was ascribed to visualization of right ventricular outflow obstruction, pulmonary valve, pulmonary arteries including dimensions, pulmonary arterial flow, systemic and pulmonary venous anatomy, atrioventricular valves, ductus arteriosus, ductus flow, aortic arch morphology, sidedness and flow).There were 10 pregnancies in Group I (12-17 weeks) and 25 in Group II (mean gestation at diagnosis 23.5 5.7). The most common reason for referral was extracardiac pathology in Group I (80%) and suspected fetal heart disease on obstetric ultrasound in Group II (64%). Transabdominal imaging was adequate in about half of Group I studies. Mean anatomic diagnosis score in Group I was 6.1(range 2.5-9) and Group II was 8.4 (range 6.5-10). Elective pregnancy termination occurred in 80% in Group I and 33% in Group II.fTOF can be diagnosed in first and early second trimesters with detailed anatomic assessment possible in most. Referral indication and pregnancy outcome differ considerably between early and later prenatal diagnosis of fTOF.
View details for DOI 10.1111/j.1540-8175.2012.01798.x
View details for Web of Science ID 000314919400021
View details for PubMedID 22963380
Multiple echocardiographic techniques have been utilized to quantify systolic function. The shortening and ejection fraction remain the most commonly used and accepted methods. However, these measures are affected by altered loading conditions, and are not applicable when ventricular geometry differs from the prolate ellipsoid typical of a left ventricle. Mitral valve annular acceleration during isovolumic contraction (IVA) has been proposed as a load independent index of left ventricular contractility. However, published values for IVA demonstrating normal function vary. In addition, the value of IVA which may discern impaired systolic function has not been established. The purpose of this study is to determine a threshold IVA value for abnormal left ventricular function in the pediatric population. Structurally/functionally normal control (n = 90) and dilated cardiomyopathy (study = 64) patients were compared for differences in left ventricular: wall stress (WS), velocity of circumferential fiber shortening (VCFc), ejection fraction (EF), ejection force, and pulsed wave-derived medial and lateral wall IVA. No difference in body surface area (p = 0.61) or gender (p = 0.53) was noted. Left ventricular ejection fraction, ejection force, VCFc, and IVA were significantly lower and WS was significantly higher in the study group (p < 0.01). The medial IVA was 1.71 0.89 m/s(2) for an EF <40%, 1.74 0.70 m/s(2) for an EF = 40-50%, 2.46 0.89 m/s(2) for an EF >50%. The lateral IVA was 1.81 1.03 m/s(2) for an EF <40%, 2.07 0.78 m/s(2) for an EF = 40-50%, 2.54 0.99 m/s(2) for an EF >50%. ROC analysis demonstrated a medial IVA of 1.97 m/s(2) as the cut-off for predicting an EF <50% with a 77% sensitivity of and specificity of 66% (AUC = 0.75, CI = 0.67-0.83, p < 0.01). ROC analysis demonstrated a lateral IVA of 2.31 m/s(2) as the cut-off for predicting an EF <50% with a 73% sensitivity of and specificity of 63% (AUC = 0.72, CI = 0.63-0.82, p < 0.01). IVA lateral of 1.93 m/s(2) or less was associated with heart transplant and death. ICC analysis demonstrated some interobserver variability in IVA measurement (0.57-0.65). The normal IVA of the medial and lateral mitral valve annulus measure over 1.97 m/s(2) and 2.31 m/s(2), respectively; values less than this cut-off are associated with EF <50%. Despite some problems with reproducibility IVA remains a promising method of screening for diminished ventricular contractility in the setting of abnormal geometry.
View details for DOI 10.1007/s00246-012-0200-4
View details for Web of Science ID 000304458900006
View details for PubMedID 22349669
Pulmonary atresia and major aortopulmonary collaterals (PA/MAPCAs) is a complex form of congenital heart disease. One to two percent of patients with PA/MAPCAs will also have total anomalous pulmonary venous connection (TAPVC). This study summarizes our surgical experience with this rare combination of life-threatening congenital heart defects.A retrospective review was performed to identify patients who had surgery for PA/MAPCAs in association with TAPVC. From November 2001 to March 2011, 9 patients presented with this combination of defects. Eight of the 9 patients had heterotaxy with an unbalanced atrioventricular canal and functional single ventricle. The ninth patient had double outlet right ventricle (two ventricles). Timing of surgical intervention was typically predicated on the degree of pulmonary venous obstruction. The median age at surgery was 14 days. All nine patients had surgical correction of TAPVC, unifocalization of MAPCA's into a central confluence, and placement of a shunt.There was one early mortality (< 30 days) and two late mortalities. For the 6 survivors, 5 have subsequently undergone a bidirectional Glenn procedure, and 3 had completion of their Fontan. Two patients are currently at the bidirectional Glenn stage; one is a good candidate for Fontan completion while the other is not suitable. The sixth patient is awaiting further assessment.The PA/MAPCAs, in association with TAPVC, is a challenging combination of defects. The data suggest that the combination of PA/MAPCAs and TAPVC can be undertaken with a reasonable midterm prognosis.
View details for DOI 10.1016/j.athoracsur.2011.06.020
View details for Web of Science ID 000296925400045
View details for PubMedID 21944736
Right ventricular end-diastolic volume (RVEDV) greater than 150 mL/m is a risk factor for sudden death in patients with tetralogy of Fallot (TOF) after repair. Because of its anterior placement and abnormal geometry, two-dimensional echocardiography is limited to a qualitative assessment of RVEDV. Cardiac magnetic resonance imaging (CMRI) and computed tomography angiography (CTA) are the accepted standards for quantifying RVEDV. This study evaluated the ability of a novel echocardiographic measure, the right ventricular annular tilt (RVAT), to identify patients with increased RVEDV.All patients with repaired TOF with an echocardiogram and CMRI or CTA were included in this retrospective study. The RVAT was determined by measuring the angle of the tricuspid valve plane relative to the mitral valve plane at end-diastole in the apical 4-chamber view in study (n = 38) and age-matched control (n = 74) patients. The RVEDV measurements were obtained by CMRI (n = 32) or CTA (n = 6). The study and control patients' ages were no different (11.3 and 11.8 years, P = .73).The study group RVAT was significantly higher than the control group RVAT (17.4 vs. 0.1 degrees; P < .0001). RVAT values greater than 20 degrees had a mean RVEDV of 166 60 mL/m, whereas RVAT less than 20 degrees had a mean RVEDV of 122 25 mL/m (P = .0370). Receiver operating characteristic analysis demonstrated an RVAT of 17.9 degrees as the cutoff for predicting a RVEDV of greater than 150 mL/m with a sensitivity of 75% and specificity of 73% (area under the curve = 0.76; confidence interval, 0.56-0.96; P = .0063). Intraclass correlation analysis demonstrated minimal interobserver and intraobserver variability when measuring RVAT (0.99 and 0.92).An RVAT less than 20 degrees is associated with an RVEDV less than 150 mL/m. RVAT is a useful echocardiographic technique for detecting increased RVEDV in patients with TOF and may help discern which patients should undergo RVEDV quantification by CMRI or CTA.
View details for DOI 10.1016/j.echo.2010.09.002
View details for Web of Science ID 000284624900012
View details for PubMedID 20950999
View details for DOI 10.1007/s00246-010-9817-3
View details for Web of Science ID 000284157400025
View details for PubMedID 20957476
Patients with 1-ventricle (1V) physiology may be at risk for peripheral arterial dysfunction at a young age. To determine whether infants and young children with 1V physiology and hypoxemia have peripheral arterial dysfunction before undergoing the Fontan operation, we measured (1) flow-mediated vasodilation (FMD) in the brachial artery, (2) serum levels of vasoactive mediators endothelin-1 (ET-1) and metabolites of nitric oxide, and (3) arterial stiffness with pulse-wave velocity (PWV) in the aorta. Eighteen patients with 1V physiology before the Fontan procedure and hypoxemia and 19 patients with normoxemia and 2-ventricle (2V) physiology were studied. Measurements were collected during cardiac catheterization. FMD in the brachial artery was the diameter gain after 4.5 minutes of forearm occlusion measured with high-resolution ultrasound and edge-detection software. Nitric oxide and ET-1 levels were measured in venous blood. PWV between the left carotid and femoral arteries was measured using pulse Doppler ultrasound. FMD was lower (2.4 +/- 3.7% vs 11.3 +/- 6%, p <0.0005) and ET-1 levels were higher (35.5 +/- 11.3% vs 24.1 +/- 9.7%, p = 0.003) in subjects with 1V physiology versus those with 2V physiology, respectively. There were no differences in nitric oxide levels or PWV. In conclusion, infants and young children with 1V physiology and hypoxemia have blunted FMD and higher ET-1 levels before undergoing the Fontan operation compared with normoxemic subjects with 2V physiology. A further understanding of pathophysiologic mechanisms underlying peripheral arterial dysfunction, including the roles of hypoxemia, low cardiac index, and ET-1, may lead to targeted therapies and improve the long-term survival of patients with 1V physiology.
View details for DOI 10.1016/j.amjcard.2008.11.059
View details for Web of Science ID 000264514100020
View details for PubMedID 19268746
This investigation sought to discern the relative accuracy of Doppler predictions of pressure drops in regurgitant jets across a broad spectrum of conditions, using an in vitro pulsatile flow model.We studied the accuracy of Doppler pressure gradients derived from regurgitant jet peak velocities using the simplified Bernoulli equation (SBE) using an in vitro flow model of atrio-ventricular valve regurgitation. We observed overall a good correlation (r = 0.89, P < 0.0001) with actual pressure gradient, when there is normal fluid viscosity and the jet is free of wall interaction. However, we observed various degrees of underestimation of pressure gradient by Doppler when regurgitant chamber size was reduced (P = 0.0003), when fluid viscosity was increased (P < 0.0001), or in the presence of wall interaction (P < 0.0001). Chamber compliance had no effect on the accuracy of pressure gradient prediction (P = 0.36). Significant underestimation error in pressure gradient prediction by Doppler of up to 43.2% was observed.When jet impingement or wall interaction are present, or when viscosity is increased, caution should be used in applying the SBE to a regurgitant jet, as significant underestimation in pressure gradient prediction may occur.
View details for DOI 10.1093/ejechocard/jen156
View details for Web of Science ID 000259408700002
View details for PubMedID 18490278
Color M-mode propagation velocity (Vp) is a measure of diastolic function in adults and, when combined with early diastolic inflow velocity (E), the ratio E/Vp reflects ventricular filling pressure. Early detection of diastolic compromise may benefit fetal patients at risk for developing heart failure. The objectives of this study were to measure values for Vp and inflow peak E in a group of normal fetuses, to analyze age-dependent alterations in these measurements, and to evaluate the interobserver and intraobserver variability of the measurements.Thirty-two normal fetuses at between 20 and 35 weeks' gestation underwent echocardiography. Color M-mode Vp was measured from the four-chamber view for the right (RV) and left (LV) ventricles, and mitral and tricuspid inflow velocities were determined by pulsed-wave Doppler ultrasound. The values obtained were compared with previously reported findings in adults.Adequate tracings were obtainable in 23 patients for the RV and 29 for the LV. Mean Vp values for the RV (15.3 +/- 3.2 cm/s) and LV (20.8 +/- 5.6 cm/s) were lower than normal adult values, and Vp values were significantly lower for the RV than the LV (P < 0.001). Applying Bazett's heart rate correction, values for RV (23.4 +/- 4.8 cm/s) and LV (31.9 +/- 8.7 cm/s) remained lower than normal adult values. There was a linear correlation of Vp with gestational age for the RV (R = 0.69, P < 0.001), and the ratio of E/Vp corrected for heart rate for the RV (1.51 +/- 0.26) remained constant throughout gestation. Interobserver bias was high but intraobserver bias low, at 19 and 1.1%, respectively.Vp is lower in fetal than in adult life. Vp for the RV changes in a manner indicative of improving diastolic function throughout normal gestation, providing insight into the alterations in diastolic function with gestation that contribute to increases in cardiac output. The use of Vp to assess diastolic function disturbance in fetuses is feasible, but high interobserver variability is problematic.
View details for DOI 10.1002/uog.5303
View details for Web of Science ID 000256107900010
View details for PubMedID 18409181
View details for PubMedID 18154968
Adults with tetralogy of Fallot (TOF) have increased long-term mortality. The identification of patients at greater risk for death or cardiac-related morbidity is challenging. This study was conducted to assess the prognostic value of cardiopulmonary exercise testing in adults with repaired TOF. One hundred eighteen consecutive adults with repaired TOF (mean age at repair 4.8 +/- 4.2 years) underwent cardiopulmonary exercise testing at a mean age of 24 +/- 8 years (range 16 to 59). The degree of pulmonary regurgitation, right ventricular function, and right ventricular systolic pressure were determined by transthoracic echocardiography. After the exercise tests, patients were regularly followed up for cardiac-related events. During a mean follow-up of 5.8 +/- 2.3 years (range 0.6 to 9.7), 9 patients died and 18 underwent hospitalization. Peak oxygen uptake (hazard ratio 0.974, 95% confidence interval 0.950 to 0.994), the slope of ventilation (VE) per unit of carbon dioxide production (VCO(2)) (hazard ratio 1.076, 95% confidence interval 1.038 to 1.115), and New York Heart Association functional class (hazard ratio 2.118, 95% confidence interval 1.344 to 3.542) were independent predictors of death or hospitalization. Patients with peak oxygen uptake < or =36% of predicted value and those with VE/VCO(2) slopes >39 were at greater risk for cardiac-related death (5-year mortality 48% vs 0%, p <0.0001, and 31% vs 0%, p <0.0001, respectively). In conclusion, the measurement of peak oxygen uptake and VE/VCO(2) slope in adults with repaired TOF can be prognostically important and could become a powerful tool to rationalize decisions regarding the prevention of premature sudden death and the need for reintervention.
View details for DOI 10.1016/j.amjcard.2006.12.076
View details for Web of Science ID 000246715900024
View details for PubMedID 17493481
To assess the utility and reliability of echocardiographic assessment of hemidiaphragm motion abnormalities in pediatric cardiothoracic patients.Retrospective observational study, with post hoc blinded assessment of echocardiographic and fluoroscopic results.Tertiary care center.Thirty-six consecutive pediatric cardiothoracic patients with suspected hemidiaphragm paralysis were identified and included in the study.None.The results of both echocardiographic and fluoroscopic studies on all patients were included. In addition, blinded review of study results were performed. The sensitivity and specificity of fluoroscopy in identifying hemidiaphragms that needed plication were 100% and 74%, respectively. The positive predictive value was 55%; negative predictive value was 100%. Comparing reported diagnoses with blinded review of the studies showed poor agreement; reviewers agreed with 89% diagnosed as normal, 44% of paralyzed, and 76% of paradoxical hemidiaphragms. The sensitivity and specificity of echo in identifying hemidiaphragms that needed plication were 100% and 81%, respectively. The positive predictive value and negative predictive value were 66% and 100%. Comparing reported diagnoses with blinded review, reviewers agreed with 97% diagnosed as normal, 81% of paralyzed, and 100% of paradoxical hemidiaphragms. Echocardiography was less accurate in discriminating between paralyzed and paradoxical diaphragm motion. Echocardiography was specific for paradoxical motion, since both patients identified by echocardiography were confirmed by fluoroscopy, but it was not sensitive. In nine patients, echo showed paralyzed motion that was identified by fluoroscopy as paradoxical.This study supports the use of echocardiography in the assessment of diaphragm function. When the diaphragms are clearly visualized by echo, as they are in the majority of cases, the addition of an additional fluoroscopic study adds no clinical value. The differentiation between paralyzed and paradoxical motion is unreliable by both imaging modalities.
View details for DOI 10.1097/01.PCC.0000227593.63141.36
View details for Web of Science ID 000241390500005
View details for PubMedID 16738495
Studies in premature animals suggest that 1) prolonged tight constriction of the ductus arteriosus is necessary for permanent anatomic closure and 2) endogenous nitric oxide (NO) and prostaglandins both play a role in ductus patency. We hypothesized that combination therapy with an NO synthase (NOS) inhibitor [N(G)-monomethyl-L-arginine (L-NMMA)] and indomethacin would produce tighter ductus constriction than indomethacin alone. Therefore, we conducted a phase I and II study of combined treatment with indomethacin and L-NMMA in newborns born at <28 weeks' gestation who had persistent ductus flow by Doppler after an initial three-dose prophylactic indomethacin course (0.2, 0.1, 0.1 mg/kg/24 h). Twelve infants were treated with the combined treatment protocol [three additional indomethacin doses (0.1 mg/kg/24 h) plus a 72-hour L-NMMA infusion]. Thirty-eight newborns received three additional indomethacin doses (without L-NMMA) and served as a comparison group. Ninety-two percent (11/12) of the combined treatment group had tight ductus constriction with elimination of Doppler flow. In contrast, only 42% (16/38) of the comparison group had a similar degree of constriction. L-NMMA infusions were limited in dose and duration by acute side effects. Doses of 10-20 mg/kg/h increased serum creatinine and systemic blood pressure. At 5 mg/kg/h, serum creatinine was stable but systemic hypertension still limited L-NMMA dose. We conclude that combined inhibition of NO and prostaglandin synthesis increased the degree of ductus constriction in newborns born at <28 weeks' gestation. However, the combined administration of L-NMMA and indomethacin was limited by acute side effects in this treatment protocol.
View details for DOI 10.1203/01.pdr.0000183659.20335.12
View details for Web of Science ID 000233416500014
View details for PubMedID 16306196
The right atrium has a significantly higher capacitance than the left atrium, and this may affect the Doppler flow pattern across an atrial septal defect (ASD) in unilateral atrioventricular (AV) valve atresia. This Doppler flow pattern is often used to assess ASD adequacy in this setting. We studied the effect of atrial capacitance and ASD size on the trans-ASD Doppler flow pattern in an in vivo flow model of alternate left or right AV valve atresia (LAVVA and RAVVA). We assessed trans-ASD Doppler flow patterns using the max/min velocity ratio and mean interatrial pressure gradients (PGs). In both models, ASD flow rate correlated with mean trans-ASD PG, but for similar flow rates the slope was higher in the LAVVA model. In LAVVA, a persistent PG was consistently observed, with low max/min ratio (median, 1.46; range, 1.03-3.13), whereas in RAVVA, phasic flow was common (median, 8.0; range, 2.8-20). Because atrial capacitance affects mean PG and Doppler flow pattern across the ASD, we propose that the assessment of ASD adequacy in RAVVA should not rely on Doppler findings.
View details for DOI 10.1016/j.echo.2004.07.015
View details for Web of Science ID 000225590900012
View details for PubMedID 15562268
View details for DOI 10.1016/j.jctvs.2004.04.008
View details for Web of Science ID 000222406100003
View details for PubMedID 15224013
We evaluated echocardiographic accuracy for defining coronary artery course in d-transposition of great arteries and the impact of a 2-reviewer method on this accuracy. The echocardiogram reports of 108 patients with d-transposition of great arteries were reviewed for coronary anatomy and compared with the operative report. In method 1, from January 1995 to December 1997, a single reader performed the echocardiogram. In method 2, from January 1998 to December 2000, 2 readers scanned individually and a consensus diagnosis was made. Comparing methods 1 and 2, the sensitivity of the echocardiogram to detect variants in coronary anatomy was 68% versus 86%, and negative predictive value was 72% versus 91%. Using a 2-reviewer method improved the accuracy of echocardiographic diagnosis of coronary anatomy with d-transposition of great arteries, aiding in risk assessment and treatment of the patient preoperatively. This study also illustrates that echocardiographic accuracy may be lower in an institution with a surgical volume more representative of the usual pediatric cardiothoracic surgical center.
View details for DOI 10.1016/j.echo.2004.02.001
View details for Web of Science ID 000221253300011
View details for PubMedID 15122186
We describe clinical and echocardiographic features of tetralogy of Fallot with absent pulmonary valve complex (TOF/APVC) and hypothesized that outcome might be related to pulmonary artery enlargement or severity of illness. We examined the clinical records of all 23 patients evaluated at our institution before death or surgical correction of TOF/APVC between 1990 and 2000. Echocardiograms for 16 patients (including 5 fetuses) were also reviewed, and measurements of the semilunar valves and pulmonary arteries were obtained and compared with patient's aortic annulus size and with established normal subjects. Actuarial survival was 15 of 23 patients (68%) at 4 years. Four fetuses were hydropic and none survived; 7 patients were ventilator dependent at operation and only 3 survived. No difference was noted in pulmonary artery diameters in survivors versus nonsurvivors. Pulmonary valve annulus size was larger in nonsurvivors (103 +/- 25% vs 71 +/- 24% of normal, p = 0.03); however, when fetal examinations were excluded, this difference did not persist. Thus, only hydrops and ventilator dependence at diagnosis predicted mortality. There was no correlation between postnatal measurements of pulmonary arteries and outcome. Larger pulmonary annulus size in hydropic fetuses and poor survival among patients diagnosed in utero suggests that the pathophysiology in TOF/APVC is not due entirely to the aneurysmal dilation of the pulmonary arteries but may be related to right-sided cardiac dysfunction.
View details for Web of Science ID 000175985300008
View details for PubMedID 12031728
The echocardiographic diagnosis of systemic venous anomalies often is rendered difficult by the variety of lesions that exist. An understanding of the embryologic processes that result in these lesions is essential for accurate identification, since these lesions often are not obvious on routine echocardiographic examination. Standard echocardiographic views may demonstrate some lesions, whereas many require modified views to outline the abnormal systemic venous anatomy. This paper reviews the basic embryologic processes of the development of the normal and abnormal systemic venous system, as well as the echocardiographic identification of these major systemic venous malformations.
View details for Web of Science ID 000170305600009
View details for PubMedID 11466154
View details for Web of Science ID 000167721100024
View details for PubMedID 11241094
Fetuses with solid, highly vascularized sacrococcygeal teratomas can die as a result of the vascular steal syndrome. This is the first report in which a percutaneous technique, radiofrequency ablation, was used to interrupt blood flow to a sacrococcygeal teratoma in 4 human fetuses.A radiofrequency ablation probe was percutaneously inserted into the fetal tumor under ultrasonographic guidance. In 2 fetuses a significant portion of the tumor mass was ablated, whereas in the other 2 fetuses only the major feeding vessels were targeted.Two infants were delivered at 28 and 31 weeks' gestation, respectively, and are doing well. In 2 other cases hemorrhage into the tumor led to an unfavorable fetal outcome.Ablation of a majority of the tumor tissue in sacrococcygeal teratoma is not necessary and proved fatal in two instances. Targeted ablation of the feeding tumor vessels diminishes blood flow sufficiently to reverse high-output fetal heart failure.
View details for Web of Science ID 000167306100041
View details for PubMedID 11228510
Serial echocardiographic studies from 11 patients who underwent the Ross procedure were reviewed, and the rate of neoaortic annulus size increase was compared with that in a normal population. The rate of growth of the neoaortic annulus after the Ross procedure was significantly greater than that in the normal population.
View details for Web of Science ID 000082536100025
View details for PubMedID 10498152
The spectral Doppler pattern at the site of an aortic coarctation (CoA) generally displays increased maximal velocity (Vmax) during systole with a slow velocity decay, resulting in the characteristic "sawtooth" pattern. If there is rapid velocity decay, the obstruction is often judged to be mild. The purpose of this study was to investigate if velocity decay is affected by proximal aortic compliance (C(p)). The relation between the velocity decay measured from the Doppler pattern and C(p) was studied with the use of an in vitro pulsatile flow model. The time (tau) between Vmax and 33% Vmax was the measure of velocity decay. The C(p) was varied from 0.7 to 2.6 mL/mm Hg for each of 4 levels of CoA severity. The various obstructions produced a Vmax range of 2.7 to 5.5 m/s. There was a positive linear relation between tau and C(p) (r(2) = 0.76). For a low C(p) (compliance = 0.7 mL/mm Hg), velocity decay was rapid (tau = 0.2 to 0.3 seconds) with no diastolic gradient. For equivalent obstructions, a high C(p) (2.6 mL/mm Hg) produced a persistent diastolic gradient and slow velocity decay (tau = 0.5 to 0.6 seconds). The Doppler pattern across a CoA is affected by C(p). Therefore, the absence of a sawtooth pattern should not exclude the diagnosis of significant CoA obstruction.
View details for Web of Science ID 000082007600005
View details for PubMedID 10441219
The relation between flow velocity and the pressure decrease is evaluated in Blalock-Taussig shunts used in congenital heart surgery and is related to the flow conditions and geometries of the shunts studied. The authors propose that the flow conditions within the shunt as well as shunt dimensions need to be taken into account when using Doppler velocimetry to predict pressure drops across these shunts.
View details for Web of Science ID 000073622900013
View details for PubMedID 9604952
The power-weighted sum of velocities (PWS) is the sum of each velocity component of the Doppler signal multiplied by its power. The purpose of this study was to determine (1) whether PWS is linearly related to volume flow and (2) whether PWS can predict the regurgitant fraction in an in vitro pulsatile flow system simulating aortic regurgitation. Doppler analysis of aortic flow was performed with an intact valve and two regurgitant valves. For each valve a linear relation between the forward flow PWS and forward flow volume was demonstrated, with excellent correlation (r = 0.99). For the valves with regurgitant orifices, the values for the PWS-derived regurgitant fraction were compared with measured regurgitant fraction. A fair correlation was demonstrated (r = 0.59), with low accuracy in prediction (error 44% +/- 24%). The PWS was inaccurate in predicting flow ratios in our in vitro system despite the strong relation with forward flow volume. The error incurred may be due to effects of filters that remove low velocity and low amplitude information.
View details for Web of Science ID 000072803200007
View details for PubMedID 9560750
View details for Web of Science ID A1995QV74200044
View details for PubMedID 7722154
View details for Web of Science ID A1995QH85500031
View details for PubMedID 7864012
Failure to repair transposition of the great arteries and ventricular septal defect in the young infant results in the early development of pulmonary vascular occlusive disease. Complete repair, preferably by an arterial switch procedure and ventricular septal defect closure, may then not be possible. We report a palliative arterial switch procedure in a 5 1/2-year-old patient with transposition, ventricular septal defect, and severe pulmonary vascular obstructive disease in whom progressive hypoxemia and exercise intolerance developed. An arterial repair without ventricular septal defect closure was performed. After the operation, the child's systemic arterial oxygen saturation and exercise tolerance have substantially improved. Although the progression of pulmonary vascular disease may not be altered, arterial repair can provide effective palliation in this subset of patients.
View details for Web of Science ID A1992JF48600032
View details for PubMedID 1379034