Kara Motonaga, MD

  • Kara S Motonaga



Work and Education

Professional Education

Albert Einstein College of Medicine, Bronx, NY, 06/02/2004


Children's Hospital Los Angeles, Los Angeles, CA, 06/30/2005


Children's Hospital Los Angeles, Los Angeles, CA, 06/30/2007


Stanford University Pediatric Cardiology Fellowship, Palo Alto, CA, 12/31/2011

Board Certifications

Adult Congenital Heart Disease, American Board of Internal Medicine

Electrophysiology, International Board of Heart Rhythm Examiners

Pediatric Cardiology, American Board of Pediatrics

Pediatrics, American Board of Pediatrics

Conditions Treated


All Publications

Extended cardiac ambulatory rhythm monitoring in adults with congenital heart disease: Arrhythmia detection and impact of extended monitoring. Congenital heart disease Schultz, K. E., Lui, G. K., McElhinney, D. B., Long, J., Balasubramanian, V., Sakarovitch, C., Fernandes, S. M., Dubin, A. M., Rogers, I. S., Romfh, A. W., Motonaga, K. S., Viswanathan, M. N., Ceresnak, S. R. 2019


BACKGROUND: Arrhythmias are a leading cause of death in adults with congenital heart disease (ACHD). While 24-48-hour monitors are often used to assess arrhythmia burden, extended continuous ambulatory rhythm monitors (ECAM) can record 2 weeks of data. The utility of this device and the arrhythmia burden identified beyond 48-hour monitoring have not been evaluated in the ACHD population. Additionally, the impact of ECAM has not been studied to determine management recommendations.OBJECTIVE: To address the preliminary question, we hypothesized that clinically significant arrhythmias would be detected on ECAM beyond 48hours and this would lead to clinical management changes.METHODS: A single center retrospective cohort study of ACHD patients undergoing ECAM from June 2013 to May 2016 was performed. The number and type of arrhythmias detected within and beyond the first 48hours of monitoring were compared using Kaplan-Meier curves and Cox proportional hazard models.RESULTS: Three hundred fourteen patients had monitors performed [median age 31 (IQR 25-41) years, 61% female). Significant arrhythmias were identified in 156 patients (50%), of which 46% were noted within 48 hours. A management change based on an arrhythmia was made in 49 patients (16%).CONCLUSIONS: ECAM detects more clinically significant arrhythmias than standard 48-hour monitoring in ACHD patients. Management changes, including medication changes, further testing or imaging, and procedures, were made based on results of ECAM. Recommendations and guidelines have been made based on arrhythmias on 48-hour monitoring; the predictive ability and clinical consequence of arrhythmias found on ECAM are not yet known.

View details for PubMedID 30604934

A Novel Pacing Maneuver to Verify the Post-Pacing Interval Minus the Tachycardia Cycle Length While Adjusting for Decremental Conduction: Using 'Dual Chamber Entrainment' for Improved Supraventricular Tachycardia Discrimination. Heart rhythm Kaiser, D. W., Nasir, J. M., Liem, L. B., Brodt, C., Motonaga, K. S., Ceresnak, S. R., Turakhia, M. P., Dubin, A. M. 2018


BACKGROUND: The post-pacing interval (PPI) minus the tachycardia cycle length (TCL) is frequently used to investigate tachycardias. However, a variety of issues (e.g. failure to entrain, decremental conduction, and oscillating TCLs) can make interpretation of the PPI-TCL challenging.OBJECTIVES: To investigate a novel maneuver to confirm the PPI-TCL value without using either the ventricular PPI or the TCL interval. To assess the ability of this maneuver to identify decremental conduction and differentiate supraventricular tachycardias.METHODS: We analyzed 77 intracardiac recordings from patients [age 2520 years, 40 female] who underwent catheter ablation of AVNRT or orthodromic reciprocating tachycardia (ORT) with a concealed pathway. We calculated the PPI-TCL, the AH-corrected PPI-TCL, and estimated the PPI-TCL using "dual chamber entrainment" calculated as: [PPIV-TCL=Stim(AoV)+Stim(VoA)-PPIA].RESULTS: The PPI-TCL calculated by dual chamber entrainment highly correlated with the observed and AH-corrected PPI-TCL [R2=0.79 and 0.96, respectively, p<0.001]. A dual chamber entrainment PPI-TCL value of 80ms correctly differentiated all AVNRT from septal ORT cases, whereas the standard PPI-TCL and AH-corrected PPI-TCL methods were incorrect in 14% and 6% of cases, respectively. Dual chamber entrainment identified 310ms of additional decremental conduction beyond AH-prolongation, including four pathways with significant (>10ms) decrement.CONCLUSION: Dual chamber entrainment estimates the PPI-TCL value without using either the ventricular PPI or the TCL interval. This maneuver adjusts for all decremental conduction, including within concealed pathways, where a dual chamber entrainment PPI-TCL value >80ms favors AVNRT over ORT. This maneuver can be used to verify the observed PPI-TCL value in challenging cases.

View details for PubMedID 30465902

Antibiotic Prophylaxis Practices in Pediatric Cardiac Implantable Electronic Device Procedures: A Survey of the Pediatric And Congenital Electrophysiology Society (PACES). Pediatric cardiology Chen, S. Y., Ceresnak, S. R., Motonaga, K. S., Trela, A., Hanisch, D., Dubin, A. M. 2018


Cardiac implantable electronic device (CIED) infections are associated with significant morbidity in the pediatric device population, with a tenfold higher risk of infection in children compared to adults. The 2010 American Heart Association (AHA) guidelines recommend a single dose of systemic antibiotic (ABX) prophylaxis prior to CIED implantation and no post-operative (OP) ABX. However, there is limited data regarding adherence to this recommendation among the pediatric community. To assess current clinical practices for CIED ABX prophylaxis in pediatrics; whether the AHA guidelines are being followed; and if not, the reasons for non-adherence. An anonymous web-based survey was sent to physician members of the Pediatric And Congenital Electrophysiology Society regarding ABX prophylaxis for new CIED implants and reoperations. 75 (25%) members responded. Only 7% of respondents follow the 2010 AHA guidelines. While all respondents give pre-OP IV ABX, 64% routinely treat patients with 24-h post-OP IV ABX with additional oral or IV therapy. 69% of respondents are cognizant of the guidelines but 88% of those cognizant do not follow the guidelines for a variety of reasons including lack of data and different substrate (pediatric patients). 79% stated that pediatric-specific data would be required for them to change their practice and follow the published guidelines. The majority of pediatric EP physicians who responded to this survey do not follow the current AHA guidelines on ABX prophylaxis and administer post-OP ABX. Most pediatric EP physicians believe that the increased risk of infection in children merits additional ABX.

View details for PubMedID 29564522

THE DEVELOPMENT AND EFFICACY OF A PEDIATRIC CARDIOLOGY FELLOWSHIP ONLINE PREPARATORY COURSE Motonaga, K., Sacks, L., Olson, I., Balasubramanian, S., Chen, S., Peng, L., Feinstein, J., Silverman, N., Hanley, F., Axelrod, D., Krawczeski, C., Ceresnak, S. ELSEVIER SCIENCE INC. 2018: 2622
A multicenter review of ablation in the aortic cusps in young people. Pacing and clinical electrophysiology : PACE Nguyen, M. B., Ceresnak, S. R., Janson, C. M., Fishberger, S. B., Love, B. A., Blaufox, A. D., Motonaga, K. S., Dubin, A. M., Nappo, L., Pass, R. H. 2017


Ablation within the aortic cusp is safe and effective in adults. There are little data on aortic cusp ablation in the pediatric literature. We investigated the safety and efficacy of aortic cusp ablation in young patients.A retrospective, descriptive study of aortic cusp ablation in five pediatric electrophysiology centers from 2008 to 2014 was performed. All patients <21 years of age who underwent ablation in the aortic cusps were included. Factors analyzed included patient demographics, procedural details, outcomes, and complications.Thirteen patients met inclusion criteria (median age 16 years [range 10-20.5] and median body surface area 1.58 m(2) [range 1.12-2.33]). Substrates for ablation included: nine premature ventricular contractions or sustained ventricular tachycardia (69%), two concealed anteroseptal accessory pathways (APs) (15%), one Wolff-Parkinson-White with an anteroseptal AP (8%), and one ectopic atrial tachycardia (8%). Three-dimensional electroanatomic mapping in combination with fluoroscopy was used in 12/13 (92%) patients. Standard 4-mm-tip radiofrequency (RF) current was used in 11/13 (85%) and low-power irrigated-tip RF in 2/13 (15%). Angiography was used in 13/13 and intracardiac echocardiography was additionally utilized in 3/13 (23%). Ablation locations included: eight noncoronary (62%), three left (23%), and two right (15%) cusps. Ablation was acutely successful in all patients. At median follow-up of 20 months, there was one recurrence of PVCs (8%). There were no ablation-related complications and no valvular injuries observed.Arrhythmias originating from the coronary cusps in this series were successfully and safely ablated in young people without injury to the coronary arteries or the aortic valve.

View details for DOI 10.1111/pace.13126

View details for PubMedID 28568013

Ventricular pacing in single ventricles-A bad combination. Heart rhythm Bulic, A., Zimmerman, F. J., Ceresnak, S. R., Shetty, I., Motonaga, K. S., Freter, A., Trela, A. V., Hanisch, D., Russo, L., Avasarala, K., Dubin, A. M. 2017; 14 (6): 853-857


Chronic ventricular pacing (VP) is associated with systolic dysfunction in a subset of pediatric patients with heart block and structurally normal hearts. The effect of chronic VP in congenital heart disease is less well understood, specifically in the single-ventricle (SV) population.To determine the longitudinal effect of VP in SV patients.SV patients with heart block and dual-chamber pacemakers requiring >50% VP were compared with nonpaced (controls) SV patients matched for age, sex, and SV morphology. Patients were excluded if a prepacing echocardiogram was not available. Echocardiogram and clinical parameters were compared at baseline (prepacing) and at last follow-up in the paced group, and in controls when they were at ages similar to those of their paced-group matches.Twenty-two paced and 53 control patients from 2 institutions were followed for similar durations (6.65 years vs 7.67.6 years; P = .59). There was no difference between groups regarding baseline ventricular function or the presence of moderate-to-severe atrioventricular valvar regurgitation (AVVR). Paced patients were more likely to develop moderate-to-severe systolic dysfunction (68% vs 15%; P < .01) and AVVR (55% vs 8%; P < .001) and require heart failure medications (65% vs 21%; P < .001). Chronic VP was also associated with a higher risk of transplantation or death (odds ratio, 4.9; 95% confidence interval, 1.05-22.7; P = .04).SV patients requiring chronic VP are at higher risk of developing moderate-to-severe ventricular dysfunction and AVVR with an increased risk of death or transplantation compared with controls. New strategies to either limit VP or improve synchronization in this vulnerable population is imperative.

View details for DOI 10.1016/j.hrthm.2017.03.035

View details for PubMedID 28528723

Advances in Pediatric Cardiology Boot Camp: Boot Camp Training Promotes Fellowship Readiness and Enables Retention of Knowledge. Pediatric cardiology Ceresnak, S. R., Axelrod, D. M., Sacks, L. D., Motonaga, K. S., Johnson, E. R., Krawczeski, C. D. 2017


We previously demonstrated that a pediatric cardiology boot camp can improve knowledge acquisition and decrease anxiety for trainees. We sought to determine if boot camp participants entered fellowship with a knowledge advantage over fellows who did not attend and if there was moderate-term retention of that knowledge. A 2-day training program was provided for incoming pediatric cardiology fellows from eight fellowship programs in April 2016. Hands-on, immersive experiences and simulations were provided in all major areas of pediatric cardiology. Knowledge-based examinations were completed by each participant prior to boot camp (PRE), immediately post-training (POST), and prior to the start of fellowship in June 2016 (F/U). A control group of fellows who did not attend boot camp also completed an examination prior to fellowship (CTRL). Comparisons of scores were made for individual participants and between participants and controls. A total of 16 participants and 16 control subjects were included. Baseline exam scores were similar between participants and controls (PRE 4711% vs. CTRL 5210%; p=0.22). Participants' knowledge improved with boot camp training (PRE 4711% vs. POST 708%; p<0.001) and there was excellent moderate-term retention of the information taught at boot camp (PRE 4711% vs. F/U 718%; p<0.001). Testing done at the beginning of fellowship demonstrated significantly better scores in participants versus controls (F/U 718% vs. CTRL 5210%; p<0.001). Boot camp participants demonstrated a significant improvement in basic cardiology knowledge after the training program and had excellent moderate-term retention of that knowledge. Participants began fellowship with a larger fund of knowledge than those fellows who did not attend.

View details for DOI 10.1007/s00246-016-1560-y

View details for PubMedID 28161811

Intranasal oxytocin treatment for social deficits and biomarkers of response in children with autism. Proceedings of the National Academy of Sciences Parker, K. J., Oztan, O., Libove, R. A., Sumiyoshi, R. D., Jackson, L. P., Karhson, D. S., Summers, J. E., Hinman, K. E., Motonaga, K. S., Phillips, J. M., Carson, D. S., Garner, J. P., Hardan, A. Y. 2017; 114 (30): 8119-8124


Autism spectrum disorder (ASD) is characterized by core social deficits. Prognosis is poor, in part, because existing medications target only associated ASD features. Emerging evidence suggests that the neuropeptide oxytocin (OXT) may be a blood-based biomarker of social functioning and a possible treatment for ASD. However, prior OXT treatment trials have produced equivocal results, perhaps because of variability in patients' underlying neuropeptide biology, but this hypothesis has not been tested. Using a double-blind, randomized, placebo-controlled, parallel design, we tested the efficacy and tolerability of 4-wk intranasal OXT treatment (24 International Units, twice daily) in 32 children with ASD, aged 6-12 y. When pretreatment neuropeptide measures were included in the statistical model, OXT compared with placebo treatment significantly enhanced social abilities in children with ASD [as measured by the trial's primary outcome measure, the Social Responsiveness Scale (SRS)]. Importantly, pretreatment blood OXT concentrations also predicted treatment response, such that individuals with the lowest pretreatment OXT concentrations showed the greatest social improvement. OXT was well tolerated, and its effects were specific to social functioning, with no observed decrease in repetitive behaviors or anxiety. Finally, as with many trials, some placebo-treated participants showed improvement on the SRS. This enhanced social functioning was mirrored by a posttreatment increase in their blood OXT concentrations, suggesting that increased endogenous OXT secretion may underlie this improvement. These findings indicate that OXT treatment enhances social abilities in children with ASD and that individuals with pretreatment OXT signaling deficits may stand to benefit the most from OXT treatment.

View details for DOI 10.1073/pnas.1705521114

View details for PubMedCentralID PMC5544319

Is There a Difference in Tachycardia Cycle Length during SVT in Children with AVRT and AVNRT? Pacing and clinical electrophysiology : PACE Mills, M. F., Motonaga, K. S., Trela, A., Dubin, A. M., Avasarala, K., Ceresnak, S. R. 2016


There are limited adult data suggesting the tachycardia cycle length (TCL) of atrioventricular reentry tachycardia (AVRT) is shorter than atrioventricular nodal reentry tachycardia (AVNRT), though little data exist in children. We sought to determine if there is a difference in TCL between AVRT and AVNRT in children.A single-center retrospective review of children with supraventricular tachycardia (SVT) from 2000 to 2015 was performed.Age 18 years, invasive electrophysiology study (EPS) confirming AVRT or AVNRT.Atypical AVNRT, congenital heart disease, antiarrhythmic medication use at time of EPS. Data were compared between patients with AVRT and AVNRT via t-test, (2) test, and linear regression.A total of 835 patients were included (12 4 years, 52 31 kg, TCL 321 55 ms), 539 (65%) with AVRT (270 Wolff-Parkinson-White, 269 concealed pathways) and 296 (35%) with AVNRT. Patients with AVRT were younger (11.7 4.1 years vs 13.0 3.6 years, P < 0.001) and smaller (49 22 kg vs 57 43 kg, P < 0.001). In the baseline state, the TCL was shorter in AVRT than AVRNT (329 51 ms vs 340 60 ms, P = 0.04). In patients requiring isoproterenol to induce SVT, there was no difference in TCL (290 49 ms vs 297 49 ms, P = 0.26). When controlling for age, there was no difference in TCL between AVRT and AVNRT at baseline or on isoproterenol. The regression equation for TCL in the baseline state was TCL = 290 + 4 (age), indicating the TCL will increase by 4 ms above a baseline of 290 ms for each year of life.When controlling for age, there is no difference in the TCL between AVRT and AVNRT in children. Age, not tachycardia mechanism, is the most significant factor in predicting TCL.

View details for DOI 10.1111/pace.12950

View details for PubMedID 27653639

Pediatric Cardiology Boot Camp: Description and Evaluation of a Novel Intensive Training Program for Pediatric Cardiology Trainees PEDIATRIC CARDIOLOGY Ceresnak, S. R., Axelrod, D. M., Motonaga, K. S., Johnson, E. R., Krawczeski, C. D. 2016; 37 (5): 834-844


The transition from residency to subspecialty fellowship in a procedurally driven field such as pediatric cardiology is challenging for trainees. We describe and assess the educational value of a pediatric cardiology "boot camp" educational tool designed to help prepare trainees for cardiology fellowship. A two-day intensive training program was provided for pediatric cardiology fellows in July 2015 at a large fellowship training program. Hands-on experiences and simulations were provided in: anatomy, auscultation, echocardiography, catheterization, cardiovascular intensive care (CVICU), electrophysiology (EP), heart failure, and cardiac surgery. Knowledge-based exams as well as surveys were completed by each participant pre-training and post-training. Pre- and post-exam results were compared via paired t tests, and survey results were compared via Wilcoxon rank sum. A total of eight participants were included. After boot camp, there was a significant improvement between pre- and post-exam scores (PRE 549% vs. POST 858%; p0.001). On pre-training survey, the most common concerns about starting fellowship included: CVICU emergencies, technical aspects of the catheterization/EP labs, using temporary and permanent pacemakers/implantable cardiac defibrillators (ICDs), and ECG interpretation. Comparing pre- and post-surveys, there was a statistically significant improvement in the participants comfort level in 33 of 36 (92%) areas of assessment. All participants (8/8, 100%) strongly agreed that the boot camp was a valuable learning experience and helped to alleviate anxieties about the start of fellowship. A pediatric cardiology boot camp experience at the start of cardiology fellowship can provide a strong foundation and serve as an educational springboard for pediatric cardiology fellows.

View details for DOI 10.1007/s00246-016-1357-z

View details for Web of Science ID 000377722400005

View details for PubMedID 26961569

Risk of cardiac disease and observations on lack of potential predictors by clinical history among children presenting for cardiac evaluation of mid-exertional syncope CARDIOLOGY IN THE YOUNG Miyake, C. Y., Motonaga, K. S., Fischer-Colbrie, M. E., Chen, L., Hanisch, D. G., Balise, R. R., Kim, J. J., Dubin, A. M. 2016; 26 (5): 894-900


This study aimed to evaluate the incidence of cardiac disorders among children with mid-exertional syncope evaluated by a paediatric cardiologist, determine how often a diagnosis was not established, and define potential predictors to differentiate cardiac from non-cardiac causes. Study design We carried out a single-centre, retrospective review of children who presented for cardiac evaluation due to a history of exertional syncope between 1999 and 2012. Inclusion criteria included the following: (1) age 18 years; (2) mid-exertional syncope; (3) electrocardiogram, echocardiogram and an exercise stress test, electrophysiology study, or tilt test, with exception of long QT, which did not require additional testing; and (4) evaluation by a paediatric cardiologist. Mid-exertional syncope was defined as loss of consciousness in the midst of active physical activity. Patients with peri-exertional syncope immediately surrounding but not during active physical exertion were excluded.A total of 60 patients met the criteria for mid-exertional syncope; 32 (53%) were diagnosed with cardiac syncope and 28 with non-cardiac syncope. A majority of cardiac patients were diagnosed with an electrical myopathy, the most common being Long QT syndrome. In nearly half of the patients, a diagnosis could not be established or syncope was felt to be vasovagal in nature. Neither the type of exertional activity nor the symptoms or lack of symptoms occurring before, immediately preceding, and after the syncopal event differentiated those with or without a cardiac diagnosis.Children with mid-exertional syncope are at risk for cardiac disease and warrant evaluation. Reported symptoms may not differentiate benign causes from life-threatening disease.

View details for DOI 10.1017/S1047951115001481

View details for PubMedID 26277987

Electrocardiographic repolarization abnormalities and increased risk of life-threatening arrhythmias in children with dilated cardiomyopathy HEART RHYTHM Chen, S., Motonaga, K. S., Hollander, S. A., Almond, C. S., Rosenthal, D. N., Kaufman, B. D., May, L. J., Avasarala, K., Dao, D. T., Dubin, A. M., Ceresnak, S. R. 2016; 13 (6): 1289-1296


Life-threatening arrhythmia events (LTEs) occur in ~5% of children with dilated cardiomyopathy (DCM). While prolonged QRS duration has been shown to be associated with LTEs, electrocardiographic (ECG) repolarization findings have not been examined.We sought to determine the associations between ECG repolarization abnormalities and LTEs in children with DCM.A single-center retrospective review of children with DCM was performed. LTEs were defined as documented ventricular tachycardia or fibrillation requiring medical intervention. Three pediatric cardiologists, blinded to clinical events, evaluated ECGs obtained at the time of initial referral. Kaplan-Meier survival and Cox proportional hazards analyses were used to evaluate time to LTEs.A total of 137 patients (mean age 7.8 6.7 years; 75(55%) male patients) with DCM (mean ejection fraction 35% 16%) were included; 67 patients (49%) had a corrected JT (JTc) interval of 340 ms, 72 (53%) had a corrected QT (QTc) interval of 450 ms, and 41 (30%) had abnormal T waves. LTEs occurred in 15 patients at a median of 12 months (interquartile range 3-36 months) after the initial ECG. Patients with LTEs had a longer JTc interval (371 77 ms vs 342 41 ms; P = .02) and a longer QTc interval (488 96 ms vs 453 44 ms; P = .01). In survival analysis, a JTc interval of 390 ms (hazard ratio [HR] 4.07; 95% confidence interval [CI] 1.12-14.83; P = .03), a QTc interval of 510 ms (HR 6.95; 95% CI 1.53-31.49; P = .01), abnormal T-wave inversion (HR 11.62; 95% CI 2.75-49.00; P = .001), and ST-segment depression (HR 6.91; 95% CI 1.25-38.27; P = .03) were associated with an increased risk of LTEs, even after adjusting for QRS duration and amiodarone use.Repolarization abnormalities are common in children with DCM. Certain ECG repolarization abnormalities, such as significantly prolonged JTc and QTc intervals, may be useful in identifying patients at risk of LTEs.

View details for DOI 10.1016/j.hrthm.2016.02.014

View details for Web of Science ID 000376334800016

View details for PubMedID 26945851

Unusual Outflow Tract Ventricular Tachycardia. Cardiac electrophysiology clinics Motonaga, K. S., Ceresnak, S. R., Hsia, H. H. 2016; 8 (1): 79-88


Distinguishing premature ventricular contractions/ventricular tachycardia from the right ventricular outflow tract versus the left ventricular outflow tract can be difficult by electrocardiogram findings alone. A thorough understanding of the outflow tract anatomy and a systematic and meticulous approach to mapping of the ventricular outflow regions and great vessels increases the success rate and decreases the risk of damage to adjacent structures and the conduction system. The use of multimodality imaging, particularly real-time intracardiac echocardiographic guidance, is essential for defining anatomy, ensuring adequate catheter contact, and minimizing risks.

View details for DOI 10.1016/j.ccep.2015.10.032

View details for PubMedID 26920175

A Pilot Study Assessing ECG versus ECHO Ventriculoventricular Optimization in Pediatric Resynchronization Patients. Journal of cardiovascular electrophysiology Punn, R., Hanisch, D., Motonaga, K. S., Rosenthal, D. N., Ceresnak, S. R., Dubin, A. M. 2016; 27 (2): 210-216


Cardiac resynchronization therapy indications and management are well described in adults. Echocardiography (ECHO) has been used to optimize mechanical synchrony in these patients; however, there are issues with reproducibility and time intensity. Pediatric patients add challenges, with diverse substrates and limited capacity for cooperation. Electrocardiographic (ECG) methods to assess electrical synchrony are expeditious but have not been extensively studied in children. We sought to compare ECHO and ECG CRT optimization in children.Prospective, pediatric, single-center cross-over trial comparing ECHO and ECG optimization with CRT. Patients were assigned to undergo either ECHO or ECG optimization, followed for 6 months, and crossed-over to the other assignment for another 6 months. ECHO pulsed-wave tissue Doppler and 12-lead ECG were obtained for 5 VV delays. ECG optimization was defined as the shortest QRSD and ECHO optimization as the lowest dyssynchrony index. ECHOs/ECGs were interpreted by readers blinded to optimization technique. After each 6 month period, these data were collected: ejection fraction, velocimetry-derived cardiac index, quality of life, ECHO-derived stroke distance, M-mode dyssynchrony, study cost, and time. Outcomes for each optimization method were compared.From June 2012 to December 2013, 19 patients enrolled. Mean age was 9.1 4.3 years; 14 (74%) had structural heart disease. The mean time for optimization was shorter using ECG than ECHO (9 1 min vs. 68 13 min, P < 0.01). Mean cost for charges was $4,400 700 less for ECG. No other outcome differed between groups.ECHO optimization of synchrony was not superior to ECG optimization in this pilot study. ECG optimization required less time and cost than ECHO optimization.

View details for DOI 10.1111/jce.12863

View details for PubMedID 26515428

Right-sided subcutaneous implantable cardioverter-defibrillator placement in a patient with dextrocardia, tetralogy of Fallot, and conduction disease. HeartRhythm case reports Ceresnak, S. R., Motonaga, K. S., Rogers, I. S., Viswanathan, M. N. 2015; 1 (4): 186-189

View details for DOI 10.1016/j.hrcr.2015.02.001

View details for PubMedID 28491545

50 is the new 70: Short ventriculoatrial times are common in children with atrioventricular reciprocating tachycardia. Heart rhythm Ceresnak, S. R., Doan, L. N., Motonaga, K. S., Avasarala, K., Trela, A. V., Reddy, C. D., Dubin, A. M. 2015; 12 (7): 1541-1547


One of the basic electrophysiological principles of atrioventricular reciprocating tachycardia (AVRT) is that ventriculoatrial (VA) times during tachycardia are >70 ms. We hypothesized, however, that children may commonly have VA times <70 ms in AVRT.This study sought to determine the incidence and characteristics associated with short-VA AVRT in children.A retrospective single-center review of children with AVRT from 2000 to 2014 was performed. All patients 18 years of age with AVRT at electrophysiology study were included. Patients with persistent junctional reciprocating tachycardia, atrioventricular nodal reentry tachycardia, and tachycardia not unequivocally proven to be AVRT were excluded. VA time was defined as the time between earliest ventricular activation and earliest atrial activation in any lead and was confirmed by 2 electrophysiologists. Patients with VA times <70 ms (SHORT-VA) and those with standard VA times 70 ms (STD-VA) were compared. Logistic regression analysis identified characteristics of SHORT-VA patients.A total of 495 patients with AVRT were included (mean age 11.7 4.1 years). There were 265 patients (54%) with concealed accessory pathways (APs) and 230 (46%) with Wolff-Parkinson-White syndrome. AP location was left-sided in 301 patients (61%) and right-sided in 194 (39%). The mean VA time in AVRT was 100 33 ms. A total of 63 patients (13%) had VA times <70 ms (SHORT-VA). The shortest VA time during AVRT was 50 ms. There was no difference in age, AV nodal block cycle, or body surface area between SHORT-VA and STD-VA patients, but SHORT-VA patients had lower weight (43 17 vs 51 23 kg, P = .02), lower AV nodal effective refractory period (AVNERP; 269 50 vs 245 52 ms, P < .01), and more left-sided APs (50 [79%] vs 251 [58%]; P < .01]. On multivariate logistic regression, factors associated with SHORT-VA included left-sided AP (odds ratio [OR] 5.79, confidence interval [95% CI] 2.21-15.1, P < .01), shorter AVNERP (OR 0.99, CI 0.98-0.99, P < .01), and lower weight (OR 0.97, CI 0.95-0.99, P < .01).Children with AVRT can frequently have VA times <70 ms, with 50 ms being the shortest VA time. This finding debunks the classic electrophysiology principle that VA times in AVRT must be >70 ms. SHORT-VA AVRT was more common in children with left-sided APs.

View details for DOI 10.1016/j.hrthm.2015.03.047

View details for PubMedID 25828598

Success Rates in Pediatric WPW Ablation Are Improved with 3-Dimensional Mapping Systems Compared with Fluoroscopy Alone: A Multicenter Study JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY Ceresnak, S. R., Dubin, A. M., Kim, J. J., Valdes, S. O., Fishberger, S. B., Shetty, I., Zimmerman, F., Tanel, R. E., Epstein, M. R., Motonaga, K. S., Capone, C. A., Nappo, L., Gates, G. J., Pass, R. H. 2015; 26 (4): 412-416


Three-dimensional mapping (3-D) systems are frequently used for ablation of supraventricular tachycardia. Prior studies have demonstrated radiation dosage reduction with 3-D, but there are no data on whether 3-D improves the efficacy of ablation of Wolff-Parkinson-White syndrome (WPW). We sought to determine if 3-D improves the success rate for ablation of WPW in children.Multicenter retrospective study including patients 21 years of age with WPW undergoing ablation from 2008 to 2012. Success rates using the 2 techniques (3-D vs. fluoroscopy alone [FLUORO]) were compared.Six hundred and fifty-one cases were included (58% male, mean age 13 4 years, 366 [56%] 3-D). Baseline characteristics including gender, weight, accessory pathway (AP) location, number of APs, and repeat ablation attempts were similar between the 2 groups (3-D and FLUORO) The 3-D group was slightly younger (12.7 4.0 vs. 13.3 4.0 years; P = 0.04) and less likely to undergo ablation utilizing cryoenergy (38 [10%] vs. 56 [20%]; P < 0.01). The 3-D group had a higher acute success rate of ablation (355 [97%] vs. 260 [91%]; P < 0.01). No differences were seen in recurrence (16 [5%] vs. 26 [9%]; P = 0.09) or complication rates (1 [0.3%] vs. 1 [0.4%]; P = 0.86) between the groups. On multivariable analysis, 3-D was shown to significantly improve success at ablation with an odds ratio of 3.1 (95% CI 1.44-6.72; P < 0.01).Use of 3-D significantly improved success rates for ablation of WPW in children. The increase in acute success associated with 3-D suggests it is an important adjunct for catheter ablation of WPW in children.

View details for DOI 10.1111/jce.12623

View details for Web of Science ID 000352814300012

View details for PubMedID 25600208

Diminished exercise capacity and chronotropic incompetence in pediatric patients with congenital complete heart block and chronic right ventricular pacing. Heart rhythm Motonaga, K. S., Punn, R., Axelrod, D. M., Ceresnak, S. R., Hanisch, D., Kazmucha, J. A., Dubin, A. M. 2015; 12 (3): 560-565


Chronic right ventricular (RV) pacing has been associated with decreased exercise capacity and left ventricular (LV) function in adults with congenital complete atrioventricular block (CCAVB), but not in children.The purpose of this study was to evaluate the exercise capacity and LV function in pediatric patients with CCAVB receiving chronic RV pacing.We prospectively evaluated pediatric patients with isolated CCAVB receiving atrial synchronous RV pacing for at least 5 years. Supine bicycle ergometry was performed, and LV ejection fraction (EF) was evaluated by echocardiography.Ten CCAVB subjects and 31 controls were matched for age, gender, and body surface area. CCAVB subjects had normal resting EF (63.1% 4.0%) and had been paced for 7.9 1.4 years. Exercise testing demonstrated reduced functional capacity in CCAVB patients compared to controls with a lower VO2peak (26.0 6.6 mL/kg/min vs 39.9 7.0 mL/kg/min, P <.001), anaerobic threshold (15.6 3.9 mL/kg/min vs 18.8 2.7 mL/kg/min, P = .007), and oxygen uptake efficiency slope (1210 406 vs 1841 452, P <.001). Maximum heart rate (165 8 bpm vs 185 9 bpm, P <.001) and systolic blood pressure (159 17 mm Hg vs 185 12 mm Hg, P <.019) also were reduced in CCAVB patients despite maximal effort (respiratory exchange ratio 1.2 0.1). EF was augmented with exercise in controls but not in CCAVB patients (13.2% 9.3% vs 0.2% 4.8% increase, P <.001).Clinically asymptomatic children with chronic RV pacing due to CCAVB have significant reductions in functional capacity accompanied by chronotropic incompetence and inability to augment EF with exercise.

View details for DOI 10.1016/j.hrthm.2014.11.036

View details for PubMedID 25433143

Ventricular lead redundancy to prevent cardiovascular events and sudden death from lead fracture in pacemaker-dependent children. Heart rhythm Ceresnak, S. R., Perera, J. L., Motonaga, K. S., Avasarala, K., Malloy-Walton, L., Hanisch, D., Punn, R., Maeda, K., Reddy, V. M., Doan, L. N., Kirby, K., Dubin, A. M. 2015; 12 (1): 111-116


Children requiring a permanent epicardial pacemaker(PM) traditionally have a single lead placed on the right ventricle. Lead failure in pacemaker dependent(PMD) children, however, can result in cardiovascular events(CVE) and death.To determine if redundant ventricular lead systems(RVLS) can safeguard against CVE and death in PMD children.Single-center study of PMD patients undergoing placement of RVLS from 2002-2013. Patients 21 years of age who were PMD were included. Patients with biventricular systems(BiV) systems placed for standard resynchronization indications were excluded. RVLS patients were compared to PMD patients with only a single pacing lead on the ventricle(SiV).769 patients underwent PM/ICD placement with 76 BiV implants and there were 49 PMD patients(6%). 13 patients underwent implantation of a RVLS. There was no difference between the RVLS group(n=13) and SiV PMD control group(n=24) with regard to age(RVLS 9.55.8 vs. SiV 9.46.7 years; p=0.52), weight(RVLS 38.232.6 vs. SiV 35.229.3 kg; p=0.62), indication for pacing, procedural complications or time to follow-up. There were 2 lead fractures (17%) in the RVLS group(mean follow-up 3.82.9 years) with no deaths or presentations with CVE. The SiV control group had 3 lead fractures (13%)(mean follow-up 2.82.9 years), with no deaths, but all 3 patients presented with CVE and required emergent PM placement.RVLS systems should be considered in children who are PMD and require permanent epicardial pacing. BiV pacing and RVLS may decrease the risk of CVEs in the event of lead failure in PMD patients.

View details for DOI 10.1016/j.hrthm.2014.09.056

View details for PubMedID 25277988

Cardiac resynchronization therapy for pediatric patients with heart failure and congenital heart disease: a reappraisal of results. Circulation Motonaga, K. S., Dubin, A. M. 2014; 129 (18): 1879-1891

View details for DOI 10.1161/CIRCULATIONAHA.113.001383

View details for PubMedID 24799504

Diagnosis and Management of Pediatric Brugada Syndrome: A Survey of Pediatric Electrophysiologists PACE-PACING AND CLINICAL ELECTROPHYSIOLOGY Harris, B. U., Miyake, C. Y., Motonaga, K. S., Dubin, A. M. 2014; 37 (5): 638-642


Brugada syndrome (BrS) can be difficult to diagnose and treat, especially in the young patient. As there is currently no consensus on the evaluation and treatment of BrS in the pediatric population, we sought to describe the current practice for the diagnosis and treatment of BrS among pediatric electrophysiologists.A web-based survey was distributed to 204 physician members (MDs) of The Pediatric and Adult Congenital Electrophysiology Society (PACES). Practice characteristics, BrS patient attributes, and diagnostic and therapeutic preferences were collected.Responses were obtained from 83 pediatric electrophysiologists. The most common initial presentation was family history. There is a large variation in testing, particularly in the use of electrophysiology (EP) studies, drug challenge testing, and genetic testing. Despite limited treatment options, there is only consensus in the therapeutic approach to the pediatric patient with symptomatic BrS with 97% of physicians recommending an implantable cardioverter defibrillator (ICD). In the asymptomatic patient, a wide variation in therapy was seen with only 27% of physicians recommending an ICD CONCLUSIONS: Significant practice variation exists among pediatric electrophysiologists with deviation from accepted diagnostic and therapeutic practices for adult BrS patients. Further studies are necessary to establish best practice guidelines for BrS in the pediatric EP community.

View details for DOI 10.1111/pace.12346

View details for Web of Science ID 000334863000016

View details for PubMedID 24456371

In-hospital arrhythmia development and outcomes in pediatric patients with acute myocarditis. American journal of cardiology Miyake, C. Y., Teele, S. A., Chen, L., Motonaga, K. S., Dubin, A. M., Balasubramanian, S., Balise, R. R., Rosenthal, D. N., Alexander, M. E., Walsh, E. P., Mah, D. Y. 2014; 113 (3): 535-540


Cardiac arrhythmias are a complication of myocarditis. There are no large studies of in-hospital arrhythmia development and outcomes in pediatric patients with acute myocarditis. This was a retrospective 2-center review of patients 21years hospitalized with acute myocarditis from 1996 to 2012. Fulminant myocarditis was defined as the need for inotropic support within 24hours of presentation. Acute arrhythmias occurred at presentation and subacute after admission. Eighty-five patients (59% men) presented at a median age of 10years (1day to 18years). Arrhythmias occurred in 38 patients (45%): 16 acute, 12 subacute, and 9 acute and subacute (1 onset unknown). Arrhythmias were associated with low voltages on the electrocardiogram (14 of 34, 41% vs 6 of 47, 13%; odds ratio [OR] 4.78, 95% confidence interval [CI] 1.60 to 14.31) and worse outcome (mechanical support, orthotopic heart transplant, or death; OR 7.59, 95% CI 2.61 to 22.07) but were not statistically significantly associated with a fulminant course, ST changes, initial myocardial function, lactate, creatinine level, C-reactive protein and/or erythrocyte sedimentation rate, or troponin I level, after adjusting for multiple comparisons. Subacute arrhythmias were associated with preceding ST changes (10 of 15, 67% vs 15 of 59, 25%, OR 5.87, 95% CI 1.73 to 19.93). All patients surviving to discharge had arrhythmia resolution or control before discharge (10 on antiarrhythmic), with 1 exception (patient with complete heart block requiring a pacemaker). At 1-year follow-up, there were 3 recurrences of ventricular arrhythmias, but no arrhythmia-related mortality. In conclusion, arrhythmias are common in pediatric patients with myocarditis, occurring in nearly 1/2 of all hospitalized children and are associated with a worse outcome. Early identification of subacute arrhythmias using electrocardiographic changes may help management. A majority of patients do not require continued postdischarge arrhythmia treatment.

View details for DOI 10.1016/j.amjcard.2013.10.021

View details for PubMedID 24332245

Electrophysiologic therapeutics in heart failure in adult congenital heart disease. Heart failure clinics Motonaga, K. S., Khairy, P., Dubin, A. M. 2014; 10 (1): 69-89


Arrhythmias have long been recognized as a major cause of morbidity and mortality in the adult with congenital heart disease. It is important that the clinician accurately diagnoses these disturbances and is cognizant of the full array of antiarrhythmic agents and devices available to treat these conditions. This review discusses the most common arrhythmias encountered in this population and the therapeutic options available. Specific issues unique to this population are also addressed.

View details for DOI 10.1016/j.hfc.2013.09.011

View details for PubMedID 24275296

Do pediatric electrophysiologists read pre-participation screening electrocardiograms more accurately than general pediatric cardiologists? journal of pediatrics Harbison, A. L., Hill, A. C., Motonaga, K. S., Miyake, C. Y., Dubin, A. M. 2013; 163 (6): 1775-1777


Pre-participation electrocardiogram (ECG) screening of athletes is controversial. Pediatric electrophysiologists do not interpret screening ECGs more accurately than pediatric cardiologists with average number of correct ECG interpretations of 13.1-12.4 (P = .14). Electrophysiologists ordered fewer follow-up tests and were more likely to give sports recommendations based on published guidelines.

View details for DOI 10.1016/j.jpeds.2013.07.034

View details for PubMedID 23993128

The effects of ketamine on dexmedetomidine-induced electrophysiologic changes in children. Paediatric anaesthesia Char, D., Drover, D. R., Motonaga, K. S., Gupta, S., Miyake, C. Y., Dubin, A. M., Hammer, G. B. 2013; 23 (10): 898-905


BACKGROUND: Dexmedetomidine is an alpha2-adrenergic agonist used for sedation and analgesia in children. We previously showed that dexmedetomidine depresses sinus and AV nodal function resulting in adverse hemodynamic effects such as bradycardia and increased blood pressure. We hypothesized that these effects of dexmedetomidine might be antagonized by co-administration of ketamine, which has sympathomimetic properties. METHODS: Twenty-two children (ages 5-17years) undergoing electrophysiologic (EP) study and ablation for supraventricular tachycardia were enrolled. Patients were kept sedated with continuous infusion of propofol at a fixed rate. Hemodynamic and EP parameters were measured before and after a loading dose of dexmedetomidine (1gkg(-1) ). A continuous infusion of dexmedetomidine (0.7gkg(-1) h(-1) ) was initiated and a ketamine loading dose (1mgkg(-1) ), followed by continuous infusion (1mgkg(-1) h(-1) ), was given. A repeat set of hemodynamic and EP parameters were then measured at the time of projected peak tissue concentration for both drugs. RESULTS: A significant increase in mean arterial pressure (MAP) was seen compared with baseline after loading of dexmedetomidine. This returned to baseline after co-administration of ketamine (mean difference between baseline and after ketamine 1.8mmHg; 95%CI, -7.8 to 4.3; P=<0.001). A decrease in heart rate was seen after dexmedetomidine followed by a return to baseline after co-administration of ketamine (mean difference between baseline and after ketamine -6.5bpm; 95%CI, -11.2 to -1.8; P=0.005). Sinus node recovery time was lengthened after dexmedetomidine but returned to baseline after ketamine (mean difference between baseline and after ketamine -16.2ms; 95%CI, -63 to 30; P=0.014). QT was prolonged after dexmedetomidine and returned to baseline after ketamine (mean difference between baseline and after ketamine -34.2ms; 95%CI, -48.4 to -20.2; P=0.004). AV nodal effective refractory period was also impaired after dexmedetomidine and showed weak evidence for return to baseline function after ketamine (mean difference between baseline and after ketamine -22.8ms; 95%CI, -40.2 to -5.2; P=0.069). CONCLUSION: The concurrent use of ketamine may mitigate the negative chronotropic effects of dexmedetomidine.

View details for DOI 10.1111/pan.12143

View details for PubMedID 23506472

Infant ventricular fibrillation after ST-segment changes and QRS widening: a new cause of sudden infant death? Circulation. Arrhythmia and electrophysiology Miyake, C. Y., Davis, A. M., Motonaga, K. S., Dubin, A. M., Berul, C. I., Cecchin, F. 2013; 6 (4): 712-718


BACKGROUND: -Ventricular arrhythmia related sudden cardiac arrest in infants with structurally normal hearts is rare. There have been no previously published reports of infants less than 3 months of age with ventricular fibrillation in which a primary diagnosis could not be defined. METHODS AND RESULTS: -Retrospective chart review of 3 unrelated infants less than 2 months of age from 3 different tertiary care centers within the United States and Australia. All 3 infants survived sudden cardiac arrest secondary to multiple episodes of polymorphic ventricular tachycardia and ventricular fibrillation. Each infant demonstrated unique and transient ECG findings consisting of ST changes and QRS widening prior to arrhythmia onset that have not been previously reported. Amiodarone, sedation, sodium channel blocking agents and/or ventricular pacing were effective in suppressing acute events. Despite thorough investigation including genetic testing, the etiology of the ventricular arrhythmias in each of these infants remains unclear. CONCLUSIONS: -This is the first report of idiopathic ventricular fibrillation in young infants preceded by stereotypical transient ECG changes. These findings may represent a new, potentially treatable cause of sudden infant death. Recognition of these prodromal changes may be important in future management and survival of these infants.

View details for DOI 10.1161/CIRCEP.113.000444

View details for PubMedID 23748209

Insights into dyssynchrony in Hypoplastic Left Heart Syndrome HEART RHYTHM Motonaga, K. S., Miyake, C. Y., Punn, R., Rosenthal, D. N., Dubin, A. M. 2012; 9 (12): 2010-2015


Cardiac resynchronization therapy has been proposed for treatment of hypoplastic left heart syndrome (HLHS) patients with right ventricular (RV) failure. The role of dyssynchrony, however, is poorly understood in this population.The purpose of this study was to better understand the relationship between electrical and mechanical dyssynchrony in HLHS using 3-dimensional electrical mapping, tissue Doppler indices of wall motion, and vector velocity imaging.Eleven HLHS subjects with normal RV function and ten normal subjects (age 3-18 years) were studied. Electrical and mechanical activation times and dyssynchrony indices (electrical dyssynchrony index, mechanical dyssynchrony index) were calculated using 3-dimensional electrical mapping, tissue Doppler indices, and vector velocity imaging.No differences in measures of electrical dyssynchrony were seen when comparing HLHS patients and normal patients (electrical activation time 63.3 22.8 ms vs 56.2 11.2 ms, P = .38; electrical dyssynchrony index 13.7 6.3 ms vs 11.6 3.0 ms, P = .34). However, measures of mechanical dyssynchrony were markedly abnormal in HLHS patients despite normal RV function (mechanical activation time 16 11.3 ms vs 0.91.9 ms, P = .01; mechanical dyssynchrony index 7.5 5.5 vs 0.4 0.8, P<.01).Patients with HLHS and preserved RV systolic function have normal electrical activation when compared to patients with normal right and left ventricles. In contrast, these patients demonstrate mechanical dyssynchrony compared to patients with normal right and left ventricles. This finding raises important questions about the indications for cardiac resynchronization therapy in this patient population.

View details for DOI 10.1016/j.hrthm.2012.08.031

View details for Web of Science ID 000311791900029

View details for PubMedID 23085485

Are wide complex tachycardia algorithms applicable in children and patients with congenital heart disease? JOURNAL OF ELECTROCARDIOLOGY Ceresnak, S. R., Liberman, L., Avasarala, K., Tanel, R., Motonaga, K. S., Dubin, A. M. 2010; 43 (6): 694-700


Several algorithms have been developed to help determine the etiology of wide complex tachycardias (WCTs) in adults. Sensitivity and specificity for differentiating supraventricular tachycardia (SVT) with aberration from ventricular tachycardia (VT) in adults have been demonstrated to be as high as 98% and 97%. These algorithms have not been tested in the pediatric population. We hypothesize that these algorithms have lower diagnostic accuracy in children and patients with congenital heart disease.A retrospective review of the pediatric electrophysiology database at Stanford from 2001 to 2008 was performed. All children with WCT, a 12-lead electrocardiogram (ECG) available for review, and an electrophysiology study confirming the etiology of the rhythm were included. Patients with a paced rhythm were excluded. The ECGs were analyzed by 2 electrophysiologists blinded to the diagnosis according to the algorithms described in Brugada et al,(2) and Vereckei et al.(5) Additional ECG findings were recorded by each electrophysiologist.A total of 65 WCT ECGs in 58 patients were identified. Supraventricular tachycardia was noted in 62% (40/65) and VT in 38% (25/65) of the ECGs. The mean age was 13.5 years (SD 5.1), the mean weight was 51.8 kg (SD 22.4), and 48% (31/65) were male. The mean tachycardia cycle length was 340 milliseconds (SD 95). Congenital heart disease (CHD) was present in 37% (24/65) of patients (7 tetralogy of Fallot, 6 Ebstein's, 4 double-outlet right ventricle, 3 complex CHD, 2 d-transposition of great arteries, 1 status-post orthotopic heart transplantation, 1 ventricular septal defect). The Brugada algorithm correctly predicted the diagnosis 69% (45/65) of the time, the Vereckei algorithm correctly predicted the diagnosis 66% (43/65) of the time, and the blinded reviewer correctly predicted the diagnosis 78% (51/65) of the time. There was no difference in the efficacy of the algorithms in patients with CHD vs those with structurally normal hearts. The findings of left superior axis deviation (P < .01) and a notch in the QRS downstroke of V(1) or V(2) (P < .01) were more common in VT than SVT, whereas a positive QRS deflection in V(1) (P = .03) was more commonly present in SVT than VT.The Brugada and Vereckei algorithms have lower diagnostic accuracy in the pediatric population and in patients with congenital heart disease than in the adult population. Left superior axis deviation and a notch in the QRS downstroke were more commonly associated with VT, whereas a positive QRS deflection in V(1) was more commonly associated with SVT in this population.

View details for DOI 10.1016/j.jelectrocard.2010.02.008

View details for Web of Science ID 000284514700039

View details for PubMedID 20382398