Pediatric Cardiology Boot Camp: Description and Evaluation of a Novel Intensive Training Program for Pediatric Cardiology Trainees
2016; 37 (5): 834-844
Electrocardiographic repolarization abnormalities and increased risk of life-threatening arrhythmias in children with dilated cardiomyopathy
2016; 13 (6): 1289-1296
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 54 ± 9 % vs. POST 85 ± 8 %; p ≤ 0.001). 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
The Benefits of 3D Mapping Systems for Ablation of WPW in Children.
Journal of cardiovascular electrophysiology
2015; 26 (10): E10-1
50 is the new 70: Short ventriculoatrial times are common in children with atrioventricular reciprocating tachycardia.
2015; 12 (7): 1541-1547
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
Wolff-Parkinson-White syndrome (WPW) and athletes: Darwin at play?
JOURNAL OF ELECTROCARDIOLOGY
2015; 48 (3): 356-361
Success Rates in Pediatric WPW Ablation Are Improved with 3-Dimensional Mapping Systems Compared with Fluoroscopy Alone: A Multicenter Study
JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY
2015; 26 (4): 412-416
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
Novel method of signal analysis for ablation of Wolff-Parkinson-White syndrome
2012; 9 (1): 2-7
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
A multicenter review of ablation in the aortic cusps in young people.
Pacing and clinical electrophysiology : PACE
Identification of the site of successful radiofrequency catheter ablation (RFCA) for Wolff-Parkinson-White (WPW) syndrome may be subjective.The purpose of this study was to develop an automated signal analysis program to predict a successful ablation site.Patients who underwent successful RFCA for WPW from 2008- 2010 at our center were analyzed. Inclusion criteria were age <21 years, loss of preexcitation in <5 seconds, and sustained success at 3 months. Exclusion criteria were congenital heart disease and pacing during RFCA. The standard recording system signal was filtered into low frequency (LF 0-≤0.02 Hz) and high frequency (HF >0.02-≤0.45 Hz). Software identified the beginning of the HF signal, LF and R-wave peaks, LF/HF signal amplitude, and area under the HF/LF signals. Successful and unsuccessful (radiofrequency energy applied without accessory pathway block) signals were compared.Thirty patients were analyzed; 16 had both successful and unsuccessful signals, and 14 had a successful ablation with 1 radiofrequency application. Mean age was 13.7 ± 3.1 years, weight 54.9 ± 22.4 kg, and time to accessory pathway ablation 1.7 ± 1.4 seconds. Significant differences were found between successful and unsuccessful signals in area under HF signal, LF amplitude, LF to R time, HF ratio, and HF area × HF ratio. A receiver operating curve of HF area × HF ratio produced an area under the curve of 0.89. An HF area × HF ratio of 3.1 distinguished successful from unsuccessful signals with 100% specificity and 81% sensitivity.Automated signal analysis retrospectively differentiated successful from unsuccessful signals in patients undergoing RFCA for WPW. This software may improve the safety and efficacy of RFCA in children.
View details for DOI 10.1016/j.hrthm.2011.08.022
View details for Web of Science ID 000298640400002
View details for PubMedID 21872561
Ventricular pacing in single ventricles-A bad combination.
2017; 14 (6): 853-857
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
Early somatic mosaicism is a rare cause of long-QT syndrome
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2016; 113 (41): 11555-11560
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 (6.6±5 years vs 7.6±7.6 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
Is There a Difference in Tachycardia Cycle Length during SVT in Children with AVRT and AVNRT?
Pacing and clinical electrophysiology : PACE
Somatic mosaicism, the occurrence and propagation of genetic variation in cell lineages after fertilization, is increasingly recognized to play a causal role in a variety of human diseases. We investigated the case of life-threatening arrhythmia in a 10-day-old infant with long QT syndrome (LQTS). Rapid genome sequencing suggested a variant in the sodium channel NaV1.5 encoded by SCN5A, NM_000335:c.5284G > T predicting p.(V1762L), but read depth was insufficient to be diagnostic. Exome sequencing of the trio confirmed read ratios inconsistent with Mendelian inheritance only in the proband. Genotyping of single circulating leukocytes demonstrated the mutation in the genomes of 8% of patient cells, and RNA sequencing of cardiac tissue from the infant confirmed the expression of the mutant allele at mosaic ratios. Heterologous expression of the mutant channel revealed significantly delayed sodium current with a dominant negative effect. To investigate the mechanism by which mosaicism might cause arrhythmia, we built a finite element simulation model incorporating Purkinje fiber activation. This model confirmed the pathogenic consequences of cardiac cellular mosaicism and, under the presenting conditions of this case, recapitulated 2:1 AV block and arrhythmia. To investigate the extent to which mosaicism might explain undiagnosed arrhythmia, we studied 7,500 affected probands undergoing commercial gene-panel testing. Four individuals with pathogenic variants arising from early somatic mutation events were found. Here we establish cardiac mosaicism as a causal mechanism for LQTS and present methods by which the general phenomenon, likely to be relevant for all genetic diseases, can be detected through single-cell analysis and next-generation sequencing.
View details for DOI 10.1073/pnas.1607187113
View details for Web of Science ID 000384886900071
View details for PubMedID 27681629
View details for PubMedCentralID PMC5068256
Unusual Outflow Tract Ventricular Tachycardia.
Cardiac electrophysiology clinics
2016; 8 (1): 79-88
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, χ(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
A Pilot Study Assessing ECG versus ECHO Ventriculoventricular Optimization in Pediatric Resynchronization Patients.
Journal of cardiovascular electrophysiology
2016; 27 (2): 210-216
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
Tricking CARTO: Cryoablation of Supraventricular Tachycardia in Children with Minimal Radiation Exposure Using the CARTO3 System
PACE-PACING AND CLINICAL ELECTROPHYSIOLOGY
2016; 39 (1): 36-41
Three-Catheter Technique for Ablation of Left-Sided Accessory Pathways in Wolff-Parkinson-White is Less Expensive and Equally Successful When Compared to a Five-Catheter Technique
PACE-PACING AND CLINICAL ELECTROPHYSIOLOGY
2015; 38 (12): 1405-1411
Right-sided subcutaneous implantable cardioverter-defibrillator placement in a patient with dextrocardia, tetralogy of Fallot, and conduction disease.
HeartRhythm case reports
2015; 1 (4): 186-189
Reducing patient radiation exposure during paediatric SVT ablations: use of CARTO (R) 3 in concert with "ALARA" principles profoundly lowers total dose
CARDIOLOGY IN THE YOUNG
2015; 25 (5): 963-968
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
Diminished exercise capacity and chronotropic incompetence in pediatric patients with congenital complete heart block and chronic right ventricular pacing.
2015; 12 (3): 560-565
"ALARA - As Low As Reasonably Achievable" protocols reduce patient radiation dose. Addition of electroanatomical mapping may further reduce dose.From 6/11 to 4/12, a novel ALARA protocol was utilised for all patients undergoing supraventricular tachycardia ablation, including low frame rates (2-3 frames/second), low fluoro dose/frame (6-18 nGy/frame), and other techniques to reduce fluoroscopy (ALARA). From 6/12 to 3/13, use of CARTO® 3 (C3) with "fast anatomical mapping" (ALARA+C3) was added to the ALARA protocol. Intravascular echo was not utilised. Demographics, procedural, and radiation data were analysed and compared between the two protocols.A total of 75 patients were included: 42 ALARA patients, and 33 ALARA+C3 patients. Patient demographics were similar between the two groups. The acute success rate in ALARA was 95%, and 100% in ALARA+C3; no catheterisation-related complications were observed. Procedural time was 125.7 minutes in the ALARA group versus 131.4 in ALARA+C3 (p=0.36). Radiation doses were significantly lower in the ALARA+C3 group with a mean air Kerma in ALARA+C3 of 13.1±28.3 mGy (SD) compared with 93.8±112 mGy in ALARA (p<0.001). Mean dose area product was 92.2±179 uGym2 in ALARA+C3 compared with 584±687 uGym2 in ALARA (p<0.001). Of the 33 subjects (42%) in the ALARA+C3 group, 14 received ⩽1 mGy exposure. The ALARA+C3 dosages are the lowest reported for a combined electroanatomical-fluoroscopy technique.Addition of CARTO® 3 to ALARA protocols markedly reduced radiation exposure to young people undergoing supraventricular tachycardia ablation while allowing for equivalent procedural efficacy and safety.
View details for DOI 10.1017/S1047951114001474
View details for Web of Science ID 000355822400018
View details for PubMedID 25155609
The Prevalence of Arrhythmias, Predictors for Arrhythmias, and Safety of Exercise Stress Testing in Children
2015; 36 (3): 584-590
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.
2015; 12 (1): 111-116
Exercise testing is commonly performed in children for evaluation of cardiac disease. Few data exist, however, on the prevalence, types of arrhythmias, predictors for arrhythmias, and safety of exercise testing in children. A retrospective review of all patients ≤21 years undergoing exercise testing at our center from 2008 to 2012 was performed. Patients with clinically relevant arrhythmias were compared to those not experiencing a significant arrhythmia. 1,037 tests were performed in 916 patients. The mean age was 14 ± 4 years, 537 (55 %) were male, 281 (27 %) had congenital heart disease, 178 (17 %) had a history of a prior arrhythmia, and 17 (2 %) had a pacemaker or ICD. 291 (28 %) patients had a rhythm disturbance during the procedure. Clinically important arrhythmias were noted in 34 (3 %) patients and included: 19 (1.8 %) increasing ectopy with exercise, 5 (0.5 %) VT, 5 (0.5 %) second degree AV block, 3 (0.3 %) SVT, and 2 (0.2 %) AFIB. On multivariate logistic regression, variables associated with the development of clinically relevant arrhythmias included severe left ventricular (LV) dysfunction on echo (OR 1.99, CI 1.20-3.30) and prior history of a documented arrhythmia (OR 2.94, CI 1.25-6.88). There were no adverse events related to testing with no patient requiring cardioversion, defibrillation, or acute anti-arrhythmic therapy. A total of 28 % of children developed a rhythm disturbance during exercise testing and 3 % were clinically important. Severe LV dysfunction and a history of documented arrhythmia were associated with the development of a clinically important arrhythmia.
View details for DOI 10.1007/s00246-014-1053-9
View details for Web of Science ID 000350034000019
View details for PubMedID 25384613
Improving ECG Services at a Children's Hospital: Implementation of a Digital ECG System.
International journal of pediatrics
2015; 2015: 697149-?
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 9.5±5.8 vs. SiV 9.4±6.7 years; p=0.52), weight(RVLS 38.2±32.6 vs. SiV 35.2±29.3 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 3.8±2.9 years) with no deaths or presentations with CVE. The SiV control group had 3 lead fractures (13%)(mean follow-up 2.8±2.9 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
Catecholaminergic polymorphic ventricular tachycardia in a child with Brugada pattern on ECG: One patient with two diseases?
2014; 11 (11): 2101-2104
Catecholaminergic polymorphic ventricular tachycardia in a child with Brugada pattern on ECG: one patient with two diseases?
2014; 11 (11): 2101-2104
Molecular diagnosis of long QT syndrome at 10 days of life by rapid whole genome sequencing
2014; 11 (10): 1707-1713
Molecular diagnosis of long QT syndrome at 10 days of life by rapid whole genome sequencing.
2014; 11 (10): 1707-1713
Background. The use of digital ECG software and services is becoming common. We hypothesized that the introduction of a completely digital ECG system would increase the volume of ECGs interpreted at our children's hospital. Methods. As part of a hospital wide quality improvement initiative, a digital ECG service (MUSE, GE) was implemented at the Children's Hospital at Montefiore in June 2012. The total volume of ECGs performed in the first 6 months of the digital ECG era was compared to 18 months of the predigital era. Predigital and postdigital data were compared via t-tests. Results. The mean ECGs interpreted per month were 53 ± 16 in the predigital era and 216 ± 37 in the postdigital era (p < 0.001), a fourfold increase in ECG volume after introduction of the digital system. There was no significant change in inpatient or outpatient service volume during that time. The mean billing time decreased from 21 ± 27 days in the postdigital era to 12 ± 5 days in the postdigital era (p < 0.001). Conclusion. Implementation of a digital ECG system increased the volume of ECGs officially interpreted and reported.
View details for DOI 10.1155/2015/697149
View details for PubMedID 26451150
Effects of Ventilation and Catheter Position on Catheter Movement on the Tricuspid Annulus during Ablation in Children.
Pacing and clinical electrophysiology : PACE
2014; 37 (8): 1051-1057
The advent of clinical next generation sequencing is rapidly changing the landscape of rare disease medicine. Molecular diagnosis of long QT syndrome (LQTS) can impact clinical management, including risk stratification and selection of pharmacotherapy based on the type of ion channel affected, but results from current gene panel testing requires 4 to 16 weeks before return to clinicians.A term female infant presented with 2:1 atrioventricular block and ventricular arrhythmias consistent with perinatal LQTS, requiring aggressive treatment including epicardial pacemaker, and cardioverter-defibrillator implantation and sympathectomy on day of life two. We sought to provide a rapid molecular diagnosis for optimization of treatment strategies.We performed CLIA-certified rapid whole genome sequencing (WGS) with a speed-optimized bioinformatics platform to achieve molecular diagnosis at 10 days of life.We detected a known pathogenic variant in KCNH2 that was demonstrated to be paternally inherited by followup genotyping. The unbiased assessment of the entire catalog of human genes provided by whole genome sequencing revealed a maternally inherited variant of unknown significance in a novel gene.Rapid clinical WGS provides faster and more comprehensive diagnostic information by 10 days of life than standard gene-panel testing. In selected clinical scenarios such as perinatal LQTS, rapid WGS may be able to provide more timely and clinically actionable information than a standard commercial test.
View details for DOI 10.1016/j.hrthm.2014.06.030
View details for PubMedID 24973560
Arrhythmias in the paediatric intensive care unit: a prospective study of the rates and predictors of arrhythmias in children without underlying cardiac disease.
Cardiology in the young
There are little data on the effect of catheter position and mechanical ventilation on ablation catheter stability during electrophysiology study in children. We sought to determine the magnitude of catheter movement with mechanical ventilation, the effect of ventilation maneuvers on catheter movement, and to compare the degree of movement observed between the right lateral (RL) and right posteroseptal (RPS) regions.From June 2012 to June 2013, patients ≤21 years of age undergoing ablation for supraventricular tachycardia with CARTO® 3 (Biosense Webster, Diamond Bar, CA, USA) were included. During mapping the ablation catheter was placed in the RPS and RL regions and the magnitude of catheter movement (mm) was measured using CARTO® 3. Measurements were made during routine ventilation and with a maximal inspiration maneuver between end-expiration (ENDEX) and peak-inspiration (PEAKINS).Twenty-one patients were included: 12 males (57%), age 13 ± 3 years, weight 55 ± 14 kg. Indications for ablation were: 10 Wolff-Parkinson-White, seven atrioventricular node re-entry tachycardia, four concealed accessory pathway. Mechanical ventilation was used in all cases. The magnitude of catheter movement was 3.6 ± 1.7 mm with routine ventilation and 6.2 ± 4.1 mm between ENDEX and PEAKINS (P ≤ 0.01). Catheter movement was greater in the RL compared to the RPS region with routine ventilation (RL 4.3 ± 1.6 vs RPS 3.0 ± 1.5; P < 0.01) and between ENDEX and PEAKINS (RL 8.3 ± 4.7 vs RPS 4.0 ± 1.7; P < 0.01).Ventilation and catheter position both have significant impact on the degree of catheter movement during ablation. Movement was greatest in the RL position. This may partially explain the lower success rates of ablation in the RL region.
View details for DOI 10.1111/pace.12393
View details for PubMedID 24666025
Ablating the anteroseptal accessory pathway-ablation via the right internal jugular vein may improve safety and efficacy
JOURNAL OF INTERVENTIONAL CARDIAC ELECTROPHYSIOLOGY
2012; 35 (3): 293-299
Arrhythmias are common in patients admitted to the paediatric intensive care unit. We sought to identify the rates of occurrence and types of arrhythmias, and determine whether an arrhythmia was associated with illness severity and paediatric intensive care unit length of stay.This is a prospective, observational study of all patients admitted to the paediatric intensive care unit at the Children's Hospital at Montefiore from March to June 2012. Patients with cardiac disease or admitted for the treatment of primary arrhythmias were excluded. Clinical and laboratory data were collected and telemetry was reviewed daily. Tachyarrhythmias were identified as supraventricular tachycardia, ventricular tachycardia, and arrhythmias causing haemodynamic compromise or for which an intervention was performed.A total of 278 patients met the inclusion criteria and were analysed. There were 97 incidences of arrhythmia in 53 patients (19%) and six tachyarrhythmias (2%). The most common types of arrhythmias were junctional rhythm (38%), premature atrial contractions (24%), and premature ventricular contractions (22%). Tachyarrhythmias included three supraventricular tachycardia (50%) and three ventricular tachycardia (50%). Of the six tachyarrhythmias, four were related to placement or migration of central venous lines and two occurred during aminophylline infusion. Patients with an arrhythmia had longer duration of mechanical ventilation and paediatric intensive care unit stay (p<0.001). In multivariate analysis, central venous lines (odds ratio 3.1; 95% confidence interval 1.3-7.2, p=0.009) and aminophylline use (odds ratio 5.1; 95% confidence interval 1.7-14.9, p=0.003) were independent predictors for arrhythmias.Arrhythmias were common in paediatric intensive care unit patients (19%), although tachyarrhythmias occurred rarely (2%). Central venous lines and use of aminophylline were identified as two clinical factors that may be associated with development of an arrhythmia.
View details for DOI 10.1017/S1047951114002339
View details for PubMedID 25434920
Characteristics of ventricular tachycardia arising from the inflow region of the right ventricle
JOURNAL OF ELECTROCARDIOLOGY
2012; 45 (4): 385-390
Ablation of anteroseptal accessory pathways have historically been associated with lower success rates and a higher risk of AV nodal injury due to close proximity to the compact AV node. We describe the technique of ablation of anteroseptal APs via the right internal jugular vein (RIJV).A retrospective analysis of all patients undergoing EP study and ablation at the Children's Hospital at Montefiore from 2008 to 2011 for SVT and/or WPW was performed. All patients less than 21 years of age who underwent ablation from the RIJV for either WPW or a concealed accessory pathway located in the anteroseptal region were included.A total of 16 patients met inclusion criteria and were the subject of this analysis. Twelve patients had WPW (75%) and four had a concealed AP (25%). Ablation was acutely successful in 94% of patients (15/16). In one patient, ablation was deferred due to close proximity to the compact AV node and risk of AV nodal injury. Radiofrequency (RF) was used in 14 patients and cryoenergy in two patients. There was no difference in WB CL pre- and post-ablation (p = 0.19). There were no complications encountered. At a mean follow-up of 15 ± 12 months, there were no recurrences.Ablation of APs in the right anteroseptal region can safely and effectively be performed via the RIJV with a success rate of 94%. This technique should be considered for ablation of APs located in the anterior septum.
View details for DOI 10.1007/s10840-012-9699-9
View details for Web of Science ID 000311313000007
View details for PubMedID 22869385
Clinical and Electrophysiologic Characteristics of Antidromic Tachycardia in Children with Wolff-Parkinson-White Syndrome
PACE-PACING AND CLINICAL ELECTROPHYSIOLOGY
2012; 35 (4): 480-488
Ventricular tachycardia (VT) arising from the right ventricular inflow (RVI) region is uncommon. There is minimal literature on the clinical and electrocardiographic characteristics of RVI VT.A retrospective analysis of patients with RVI VT who underwent electrophysiology study between 2006 and 2011 was performed. Patients with structural heart disease (including arrhythmogenic right ventricular dysplasia) were excluded.Seventy patients underwent an electrophysiology study for VT arising from the right ventricle during the study period. Nine patients (13%) met the inclusion criteria for RVI VT and were the subject of this analysis. The median age was 46 years (range, 14-71), and VT cycle length was 295 milliseconds (range, 279-400 milliseconds). All VTs had an left bundle-branch block morphology. An inferiorly directed QRS axis was noted in 7 (78%) of 9 patients and a left superior axis in 2 (22%) of 9 patients. A QS or rS pattern was noted in all patients in aVR and V(1). A transition from S to R wave occurred in V(3) to V(5) in all patients, with 78% of the patients transitioning in V(4) or V(5). Ablation was attempted in 8 (89%) of 9 patients and was successful in 6 (67%) of 9 patients. Ablation was limited in all unsuccessful patients due to the proximity to the His and risk of complete heart block.Electrocardiographic findings of a left bundle-branch block with a normal QRS axis, QS or rS patterns in aVR and V(1), and late S to R transition (V(4)/V(5)) are commonly found in RVI VT. Because of the proximity to the His, ablation of RVI VT may be more challenging than that of right ventricular outflow tract VT.
View details for DOI 10.1016/j.jelectrocard.2012.03.009
View details for Web of Science ID 000306153000010
View details for PubMedID 22554461
Late Onset Ictal Asystole in Refractory Epilepsy
2011; 45 (4): 253-255
Antidromic reciprocating tachycardia (ART) is a rare form of wide complex tachycardia in children with Wolff-Parkinson-White syndrome (WPW). The incidence and electrophysiologic characteristics of ART in children with WPW have not been well described.A multicenter retrospective analysis of all patients with WPW undergoing electrophysiology (EP) study from 1990 to 2009 was performed. Patients with clinical or inducible ART were included.A total of 1,147 patients with WPW underwent EP study and 30 patients had ART (2.6%) and were the subject of this analysis. The mean age was 16±3 years, weight was 65±16 kg, and tachycardia cycle length was 305±55 ms. There were two patients (7%) with congenital heart disease (both with Ebstein's anomaly). Four patients (13%) had more than one accessory pathway (AP). The location of the AP was left sided in 53% of patients and right sided in 47%, with septal location and left lateral pathways most commonly involved. AP conduction was found to be high risk in 17 patients (57%). Ablation was not attempted in two patients (7%) due to proximity to the HIS and risk of heart block. Ablation was acutely successful in 93% of the patients in whom it was attempted.ART is a rare finding in children undergoing EP study. Over half of the patients with ART were found to be high risk and multiple AP were uncommon. Unlike the adult population, ART occurred commonly with septal APs.
View details for DOI 10.1111/j.1540-8159.2011.03317.x
View details for Web of Science ID 000302540300024
View details for PubMedID 22324823
Electrocardiograms Transmitted via Facsimile May Not Allow Accurate Interval Interpretation
PACE-PACING AND CLINICAL ELECTROPHYSIOLOGY
2011; 34 (10): 1283-1287
Ictal asystole is a cardiac phenomenon associated with epileptic seizures, and may play a role in sudden unexplained death in epilepsy. We present a 17-year-old boy with chronic intractable epilepsy and a vagus nerve stimulator who developed ictal asystole many years after the onset of epilepsy. The asystole was not linked to the vagus nerve stimulator, and ultimately necessitated the placement of a cardiac pacemaker. A cardiac pacemaker and vagus nerve stimulator can be safely used simultaneously after careful testing during placement. The onset of asystolic events many years after the onset of epilepsy suggests that repeated seizures may exert long-term effects on cardiac function.
View details for DOI 10.1016/j.pediatrneurol.2011.07.005
View details for Web of Science ID 000295244900009
View details for PubMedID 21907888
Ex Vivo Cryoablation of Wolff-Parkinson-White in a Donor Heart Prior to Pediatric Heart Transplantation
AMERICAN JOURNAL OF TRANSPLANTATION
2011; 11 (9): 1986-1988
Electrocardiograms (ECGs) are sent via facsimile by pediatricians and psychiatrists to cardiologists for assessment. The validity of this method of transmission has not been established. ECGs were collected from 100 consecutive patients from the cardiology clinic of the Children's Hospital at Montefiore. The ECGs were faxed and also electronically faxed (efax) and printed. Two electrophysiologists (EP1 and EP2) interpreted the intervals on original, faxed, and efaxed ECGs and intervals (RR, PR, and QT) were compared. A three-way analysis of variance to examine differences between raters, among ECG intervals, and among methods (repeated factor) was performed. Because no interaction terms were significant, a Duncan's multiple range test was used to evaluate where differences occurred among the three intervals and three methods, given these main effects were significant. The difference between raters EP1 and EP2 was not significant (P = 0.6681). Although the interval measurements of the faxed and efaxed ECGs were not significantly different from each other (P > 0.05), each was significantly different from the original across all three ECG intervals and both raters (P = 0.0138). The RR interval yielded mean (SD) values for the original, faxed, and efaxed methods of 0.6986 seconds (0.2074), 0.6646 seconds (0.1938), and 0.6838 seconds (0.1935), respectively. For the QT interval, the mean (SD) values for the original, faxed, and efaxed methods were 0.3370 seconds (0.0524), 0.32134 seconds (0.0466), and 0.3284 seconds (0.0515), respectively. ECG transmission via facsimile or efax may introduce significant distortion of the intervals. Alternative means of sending ECGs for interpretation should be considered.
View details for DOI 10.1111/j.1540-8159.2011.03158.x
View details for Web of Science ID 000296051400016
View details for PubMedID 21995491
Wolff-Parkinson-White Syndrome and Isoproterenol Testing in Children A Valid Adjunct to Predict Risk?
CIRCULATION-ARRHYTHMIA AND ELECTROPHYSIOLOGY
2011; 4 (1): 8-10
Predictors for hemodynamic improvement with temporary pacing after pediatric cardiac surgery
JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY
2011; 141 (1): 183-187
This report describes the use of a donor heart with ventricular pre-excitation for pediatric orthotopic heart transplantation and the successful surgical cryoablation of the donor heart prior to transplantation. The issues related to the preoperative evaluation and surgical management of the donor heart with Wolff-Parkinson White syndrome are discussed.
View details for DOI 10.1111/j.1600-6143.2011.03657.x
View details for Web of Science ID 000294360400029
View details for PubMedID 21794085
Are wide complex tachycardia algorithms applicable in children and patients with congenital heart disease?
JOURNAL OF ELECTROCARDIOLOGY
2010; 43 (6): 694-700
Temporary epicardial pacing wires are commonly placed during pediatric cardiac surgery. Data are sparse on postoperative pacing in this population. The objective of this study was to determine the frequency of use and identify predictors for the use of temporary epicardial pacing wires.Perioperative data were prospectively collected on all patients who underwent cardiac surgery at our institution (n = 162).A total of 117 (72%) patients had temporary epicardial pacing wires placed. Postoperatively, 23 (20%) of 117 patients had hemodynamic improvement with the use of temporary epicardial pacing wires. Indications for pacing were slow junctional rhythm (11/23 [48%]), junctional ectopic tachycardia (7/23 [31%]), pace termination of supraventricular tachycardia (3/23 [13%]) and atrial flutter (1/23 [4%]), and complete heart block (1/23 [4%]). By using univariate analysis, single-ventricle anatomy, heterotaxy, the Fontan procedure, use of circulatory arrest, intraoperative arrhythmia, pacing in the operating room, and use of vasoactive medications were predictors for hemodynamic improvement with the use of temporary epicardial pacing wires (P < .05). On multivariate analysis, the Fontan procedure, circulatory arrest, and intraoperative arrhythmias were independent predictors (P < .01). When excluding all patients with any of these 3 risk factors, only 2% were paced. Patients with clinically significant pacing had longer chest tube drainage (P < .01) and intensive care unit length of stay (P < .01). There were no complications associated with temporary epicardial pacing wires.The Fontan procedure, use of circulatory arrest, and intraoperative arrhythmias were associated with hemodynamic improvement with postoperative pacing and might represent indications for empiric intraoperative placement of temporary epicardial pacing wires. Patients without these risk factors were less likely to require pacing. Temporary epicardial pacing wires were safe and useful in the management of arrhythmias after pediatric cardiac surgery.
View details for DOI 10.1016/j.jtcvs.2010.03.048
View details for Web of Science ID 000285407500032
View details for PubMedID 20656300
Cryoablation with an 8-mm Tip Catheter for Pediatric Atrioventricular Nodal Reentrant Tachycardia Is Safe and Efficacious with a Low Incidence of Recurrence
PACE-PACING AND CLINICAL ELECTROPHYSIOLOGY
2010; 33 (6): 681-686
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
Survival of Transvenous ICD Leads in Young Patients
PACE-PACING AND CLINICAL ELECTROPHYSIOLOGY
2010; 33 (2): 186-191
Cryoablation with 4- and 6-mm tip ablation catheters has been demonstrated to be safe and effective in the treatment of atrioventricular nodal reentrant tachycardia (AVNRT) in pediatric patients, albeit with a higher rate of clinical recurrence. Limited information is available regarding efficacy, mid-term outcomes, and complications related to the use of the 8-mm Freezor Max Cryoablation catheter (Medtronic, Minneapolis, MN, USA) in pediatric patients.We performed a retrospective review of all pediatric patients with normal cardiac anatomy who underwent an ablation procedure for treatment of AVNRT using the 8-mm tip Cryoablation catheter at three large pediatric academic arrhythmia centers.Cryoablation with an 8-mm tip catheter was performed in 77 patients for treatment of AVNRT (female n = 40 [52%], age 14.8 +/- 2.2 years, weight 62.0 +/- 13.9 kg). Initial procedural success was achieved in 69 patients (69/76, 91%). Transient second- or third-degree atrioventricular (AV) block was noted in five patients (6.5%). There was no permanent AV block. Of the patients successfully ablated with Cryotherapy, there were two recurrences (2/70, 2.8%) over a follow-up of 11.6 +/- 3.3 months.Cryoablation with an 8-mm tip ablation catheter is both safe and effective with a low risk of recurrence for the treatment of AVNRT in pediatric patients.
View details for DOI 10.1111/j.1540-8159.2010.02706.x
View details for Web of Science ID 000278818200006
View details for PubMedID 20230479
An epicardial pacing safety net: an alternative technique for pacing in the young
CARDIOLOGY IN THE YOUNG
2009; 19 (3): 228-232
In adults, transvenous implantable cardioverter defibrillator (ICD) lead failure rates are significant, and their occurrence increases with time from implant. There are limited data in children. The goal of this study was to assess lead survival in young patients undergoing ICD implantation at a single center.Records of patients under 21 years old with transvenous ICD leads implanted at our center from June 1997 to August 2007 were retrospectively reviewed. Age, weight, height, diagnosis, lead and generator model, venous access technique, generator position, pacing thresholds, lead impedance, and R wave size were recorded. "Lead failure" was defined as any lead problem requiring surgical intervention to restore proper function to the ICD system.Seventy-one transvenous leads were included (70 patients). Average age at implant was 14.8 years (range 5.7-19.5). All the devices were implanted by a single operator (HMS). Venous access was obtained via cephalic cutdown in 66/71. Mean follow-up time was 2.8 years (range 0.2-7.8 years, median 2.3 years). There were no infections requiring explantation. There were four lead failures. Three were lead fractures, occurring 12, 13, and 19 months after implant. The fourth lead failed when an arrhythmia was not appropriately detected, and a second dedicated rate-sensing lead was thus implanted. Univariate analysis did not identify any variable to be a significant predictor of lead failure. Kaplan-Meier survival analysis demonstrated 5-year lead survival at 89.6%.ICD lead survival in children, when performed by an experienced operator, is similar to that found in adults.
View details for DOI 10.1111/j.1540-8159.2009.02600.x
View details for Web of Science ID 000273901500013
View details for PubMedID 20002886
Elevated Impedance During Cardioversion in Neonates with Atrial Flutter
2009; 30 (4): 436-440
Epicardial pacing is the standard approach for permanent pacing in small children and patients with functionally univentricular physiology. The longevity of epicardial leads, however, is compromised by increased occurrences of exit block and lead fractures. We report our experience with a technique of placing a second ventricular lead, and attaching it to the atrial port of a dual chamber pacemaker to prevent the need for early re-operation in the event of failure of the primary epicardial lead. A retrospective review showed that, over the period from 2001 through 2007, epicardial ventricular pacemakers had been placed in 88 patients. In 6 of these, we had placed 2 ventricular leads, their median weight being 8.0 kilograms, with a range from 4.2 to 31.8 kilograms. Fracture of a lead occurred in 1 of the patients (17%) 8 months after placement, requiring reprogramming to pace from the atrial port. This possibility avoided the need for repeated emergent surgery. At a median follow-up of 1.5 years, with a range from 0.3 to 4.4 years, there have been no complications. During the same time period, overall failure of epicardial leads at our institution was 13%. Placement of a second ventricular epicardial pacing lead, attached to the atrial port of a dual chamber pacemaker, therefore, may provide a safe and effective means of ventricular pacing in the setting of epicardial lead failure, and may obviate the need for repeat, potentially urgent, pacemaker surgery.
View details for DOI 10.1017/S1047951109003710
View details for Web of Science ID 000266792000003
View details for PubMedID 19272204
Verapamil sensitive ventricular tachycardia associated with a cardiac hemangioma in the right ventricular outflow tract.
Indian pacing and electrophysiology journal
2009; 9 (6): 355-359
Direct-current cardioversion is a common treatment modality for acute termination of atrial flutter in neonates. Studies in children have demonstrated that cardioversion is often successful with as little as 0.25-0.5 J/kg with the current biphasic devices. We hypothesize that during cardioversion of atrial flutter in neonates, however, the impedance may be high and more energy may be required for successful cardioversion. A retrospective chart review of our institutional experience from 2005 through 2008 was performed. Neonates with atrial flutter requiring cardioversion who had strips available for review were included. Six patients met the inclusion criteria. The median age at the time of cardioversion was 2.6 h (range, 1.3-336 h) and the mean weight was 3.22 +/- 0.4 kg (SD). The mean electrical impedance of the successful shocks was elevated, at 234 +/- 136 Omega. The mean energy delivered for successful cardioversion was 0.9 +/- 0.3 J/kg, and the current was 1 A in all patients. In conclusion, the shock impedance was elevated in the neonates studied during cardioversion of atrial flutter. Low current was sufficient for successful cardioversion. Further studies are needed in this specific population.
View details for DOI 10.1007/s00246-009-9413-6
View details for Web of Science ID 000266167600008
View details for PubMedID 19365665
The palliative arterial switch procedure for single ventricles: Are these patients suitable Fontan candidates?
ANNALS OF THORACIC SURGERY
2008; 86 (2): 583-587
Primary tumors of the heart are rare, but they are often associated with refractory arrhythmias. Vascular tumors of the heart comprise a small minority of primary cardiac tumors. In patients with structurally normal hearts, ventricular tachycardia (VT) originating from the right ventricular outflow tract (RVOT) can be sensitive to adenosine, vagal maneuvers, and calcium channel blockers. In this report, we describe a case of ventricular tachycardia originating from within a hemangioma in the RVOT that was ultimately controlled with verapamil.
View details for PubMedID 19898659
Coronary Artery Fistulas: A Review of the Literature and Presentation of Two Cases of Coronary Fistulas with Drainage into the Left Atrium
Congenital Heart Disease
2007; 2 (3): 208-213
Amino acid profile of escaped feed protein after rumen incubation and their intestinal digestibility
ARCHIVES OF ANIMAL NUTRITION
2002; 56 (6): 409-418
The traditional first stage of palliation for functional single-ventricle lesions with transposition of the great vessels and systemic outflow tract obstruction has been either the Norwood or Sano procedure or the Damus-Kaye-Stansel procedure. There is limited literature on the use of an arterial switch procedure as the initial staged palliation for functional single ventricles in this setting. This study is an examination of our institutional experience with performing the palliative switch procedure with examination of suitability for Fontan completion and midterm outcome in these patients.This is a retrospective review of our institutional experience from October 1991 through August 2006 on single-ventricle patients with transposition of the great vessels and systemic outflow tract obstruction who underwent a palliative arterial switch procedure.Nine patients underwent an initial palliative switch procedure. Six of 9 patients underwent completion of palliation with the Fontan procedure and are alive and well. One patient is well and is awaiting the next stage of palliation (78%). There was 1 early operative death (11%) and 1 late death (11%). There was 1 case of recoarctation (11%).The palliative switch procedure appears a reasonable surgical option for patients with functional single-ventricle lesions, transposition of the great vessels, and systemic outflow tract obstruction. Patients who have undergone a palliative switch procedure are suitable candidates for completion of palliation with the Fontan procedure.
View details for DOI 10.1016/j.athoracsur.2008.04.022
View details for Web of Science ID 000257767100034
View details for PubMedID 18640337
The crude protein content and amino acid profile of seven feedstuffs (linseed meal, maize gluten meal, rapeseed meal, rapeseed meal protected, soybean meal, fullfat soybean extruded and sunflower meal) were determined before and after ruminal incubation for 16 h in three bulls with large rumen cannulas. The intestinal disappearance of amino acids was measured using mobile bag technique. Ruminal incubation affected amino acid profile of all experimental feedstuffs. Crude protein degradation varied from 29.3% for maize gluten meal to 86.4% for rapeseed meal. A tendency towards increased disappearance was observed for glutamic acid, histidine, lysine and proline and decreased disappearance for branched-chain amino acids. The intestinal crude protein digestibility was higher than > 80%, except rapeseed meal (66.4%) and sunflower meal (77.8%). The least digestible individual amino acids were methionine and isoleucine in rapeseed meal, histidine and methionine in rapeseed meal protected and arginine in sunflower meal. In general, the lowest amino acid digestibilities were found in feedstuffs with the highest fibre content. The feedstuffs show that they have different potential for supplying of limiting amino acids. Of particular value are the feedstuffs with low crude protein degradability in the rumen and high intestinal digestibility of amino acids.
View details for DOI 10.1080/0003942921000019135
View details for Web of Science ID 000180621800003
View details for PubMedID 12553691