Maully J. Shah

The use of implantable cardioverter-defibrillators in pediatric patients awaiting heart transplantation

BACKGROUND This multicenter study evaluated experience with implantable cardioverter defibrillators (ICD) as a bridge to orthotopic heart transplantation (OHT) in children. METHODS The application of ICD therapy continues to expand in pediatric populations, due in part to improved technology and new indications, including the prevention of sudden death while awaiting OHT. METHODS We performed a retrospective review of ICD databases at 9 pediatric transplant centers. RESULTS Twenty-eight patients (16 males) underwent implantation or had a preexisting ICD while awaiting OHT between 1990 and 2002. The median age at implant was 14.3 years (11 months to 21 years) with a median weight of 49 kg (11.7-88 kg). Diagnoses included cardiomyopathy (n=22), and congenital heart disease (n=6). Indications for ICD implantation included ventricular tachycardia/fibrillation (n=23), syncope (n=5), aborted sudden death with no documentation of rhythm disturbance (n=5), ventricular ectopy (n=1), and poor function (n=5). Of the 28 ICDs, 23 were implanted by a transvenous approach and 5 by epicardial route. There were 55 defibrillator discharges in 17 patients, 47 (85%) of which (in 13 patients) were appropriate. The 8 inappropriate discharges (in 6 patients) were triggered by sinus tachycardia, inappropriate sensing, and atrial flutter. The mean time from implantation to first appropriate shock was 6.9 months (1 day to 2.6 years). Twenty-one patients underwent transplantation during the study period, whereas 2 died while awaiting a donor. Morbidity included a lead fracture, 3 episodes of electromechanical dissociation, and 1 episode of electrical storm. CONCLUSIONS ICD implantation represents an effective bridge to transplantation in pediatric patients. The complication rate is low, with inappropriate device discharge due primarily to sinus tachycardia or atrial flutter. There is a high incidence of appropriate ICD therapy for malignant ventricular arrhythmias in this highly selected group of patients.

Endocardial Atrial Pacing Lead Implantation and Midterm Follow-Up in Young Patients with Sinus Node Dysfunction After the Fontan Procedure

The purpose of the study was to investigate the results of endocardial lead implantation, lead performance, and follow‐up in young patients after the Fontan procedure. A retrospective study was conducted with patients who had endocardial atrial pacing for SND and intact AVN function after Fontan from two pediatric centers. Patient demographics, pacing, and sensing data of endocardial atrial leads were analyzed at the time of pacemaker implantation and follow‐up visits. Fifteen patients (weight 42.6 ± 35 kg) had transvenous endocardial atrial lead implantation at an average age of 11.4 ± 6.5 years. Active‐fixation leads were used in all patients and steroid elution was present in 12 (80%) patients. Adequate P wave sensing was obtained in patients with sinus rhythm (n = 10); the remaining four patients had junctional rhythm without measurable P waves. Lead failure was not observed in any patient during the follow‐up period of 2.9 ± 2.1 years. The energy threshold at implantation was 1.46 ± 1.5 μJ, 1.54 ± 0.75 μJ at 3 months, 0.62 ± 0.45 μJ at 1 year, 0.72 ± 0.65 μJ at 2 years, 0.75 ± 0.55 μJ at 3 years, and 0.8 ± 0.85 μJ at 5 years postimplant. The lead impedance was 648 ± 298 Ω at implantation, 714 ± 163 Ω at 3 months, 744 ± 195 Ω at 1 year, 734 ± 198 Ω at 2 years, 800 ± 142 Ω at 3 years and 830 ± 200 Ω 5 years postimplant. Anticoagulation therapy (aspirin n = 5, warfarin n = 8) was continued by 13 patients. Complications consisted of a pneumothorax at implantation and a transient ischemic attack in one patient 4 years after pacemaker implant. Endocardial atrial leads offer low energy thresholds and can be implanted relatively safely in Fontan patients. (PACE 2004; 27:949–954)

Improved localization of right-sided accessory pathways with microcatheter-assisted right coronary artery mapping in children.

Introduction: Radiofrequency ablation of some right‐sided accessory pathways continues to be challenging. The purpose of this study was to evaluate the efficacy of introducing a multielectrode microcatheter in the right coronary artery to localize accessory pathways when conventional mapping was unsuccessful.

Catheter ablation of a right atrial appendage to the right ventricle connection in a neonate.

SHAH, M.J., et al.: Catheter Ablation of a Right Atrial Appendage to the Right Ventricle Connection in a Neonate. A neonate with incessant supraventricular tachycardia refractory to multiple antiarrhythmic medications was referred to our institution for radiofrequency ablation. An unusual accessory pathway between the right atrial appendage and right ventricle was successfully ablated. This case also emphasizes the congenital origin of such an accessory pathway.

Task Force 4: Pediatric Cardiology Fellowship Training in Electrophysiology. SPCTPD/ACC/AAP/AHA.

### 1.1 Document Development Process The Society of Pediatric Cardiology Training Program Directors (SPCTPD) board assembled a Steering Committee that nominated 2 chairs, 1 SPCTPD Steering Committee member, and 5 additional experts from a wide range of program sizes, geographic regions, and