Safety of Sports for Young Patients With Implantable Cardioverter-Defibrillators: Long-Term Results of the Multinational ICD Sports Registry.

BACKGROUND: Despite safety concerns, many young patients with implantable cardioverter-defibrillators (ICDs) participate in sports. We undertook a prospective, multinational registry to determine the incidence of serious adverse events because of sports participation. The primary end points were death or resuscitated arrest during sports or injury during sports because of arrhythmia or shock. Secondary end points included system malfunction and incidence of ventricular arrhythmias requiring multiple shocks for termination. METHODS: Athletes with ICDs aged ≤21 years were included in this post hoc subanalysis of the ICD Sports Registry. Data on sports and clinical outcomes were obtained by phone interview and medical records review. ICD shocks and clinical details of lead malfunction were classified by 2 electrophysiologists. RESULTS: A total of 129 young athletes participating in competitive (n=117) or dangerous (n=12) sports were enrolled. The mean age was 16 years (range, 10-21; 40% female; 92% white). The most common diagnoses were long QT syndrome (n=49), hypertrophic cardiomyopathy (n=30), and congenital heart disease (n=16). The most common sports were basketball and soccer, including 79 varsity/junior varsity high school and college athletes. During a median follow-up of 42 months, 35 athletes (27%) received 38 shocks. There were no occurrences of death, arrest, or injury related to arrhythmia, during sports. There was 1 ventricular tachycardia/ventricular fibrillation storm during competition. Freedom from lead malfunction was 92.3% at 5 years and 79.6% at 10 years. CONCLUSIONS: Although shocks related to competition/practice are not uncommon, there were no serious adverse sequelae. Lead malfunction rates were similar to previously reported in unselected pediatric ICD populations. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov . Unique identifier: NCT00637754.

Bipolar lumenless lead performance in children and adults with congenital heart disease.

BACKGROUND: Because of small size and anatomic variation, implantation of intracardiac leads for permanent pacing in pediatric and congenital heart disease (CHD) patients can be challenging. A novel 4.1F bipolar catheter-delivered lead offers potential advantages for this population. OBJECTIVE; The purpose of this study was to retrospectively evaluate this lead performance in this specific population. METHODS: We performed a retrospective descriptive analysis of all pediatric and adult CHD patients at a single center implanted with a 4.1F bipolar catheter-delivered active fixation pacemaker lead (Medtronic model 3830, Medtronic, Inc, Minneapolis, MN, USA). RESULTS: Over 10 months, 42 leads were implanted in 27 patients. Twenty-six atrial and 16 ventricular leads were placed. Patient ages were 1-28 years (mean 15 +/- 7), and weights were 7.8-104 kg (mean 51.5 +/- 26.6). Ventricular septal defect and D-transposition of great arteries were the most prevalent CHD diagnoses. Implant capture thresholds were 1.2 +/- 0.8 V at 0.5 ms in the atrium and 0.8 +/- 0.5 V at 0.5 ms in the ventricle. Implant sensing thresholds were 4.1 +/- 2.7 mV in the atrium and 12.1 +/- 4.9 mV in the ventricle. Phrenic nerve stimulation was avoided in all, and selective site pacing was achieved in most cases. Pacing and sensing thresholds remained stable during 90 +/- 52 days follow-up. No lead related complications, failures, or extractions were observed. CONCLUSIONS: In our single-center experience with pediatric and CHD patients, a novel small, catheter-delivered bipolar lead has proven safe and effective for atrial and ventricular pacing in acute and subacute time periods. Longer performance trends will be required to determine chronic efficacy.

Transtelephonic electrocardiographic monitors for evaluation of children and adolescents with suspected arrhythmias.

OBJECTIVE: Patient-activated transtelephonic electrocardiographic event monitors (TTMs) are often used for the evaluation of children and adolescents with suspected arrhythmias. Since their introduction 25 years ago, there has been little inquiry quantifying the usefulness of TTMs for pediatric patients. The objective of this study was to measure the utility of TTMs for children and adolescents with symptoms of a possible cardiac rhythm disturbance. METHODS: Medical records of all patients who received TTMs from C.S. Mott Children's Hospital Electrocardiography Laboratory between February 1, 1993, and October 31, 2000, were reviewed. Patients with pacemakers, known arrhythmias, or age older than 18 years were excluded. Indications for monitoring included palpitations with or without other symptoms (N = 420), chest discomfort (N = 43), and presyncope or syncope (N = 32). RESULTS: A total of 495 studies (patient mean age: 10.2 +/- 4.3 years; range: 0.1-17.9 years; 48% male) met inclusion criteria. Monitoring was performed for 1 to 1021 consecutive days (mean: 103 +/- 97). Fifty-two percent (N = 257) of patients failed to transmit an electrocardiogram while experiencing symptoms. Fewer boys transmitted electrocardiograms (N = 100/238). Of 238 symptomatic patients, 15% (N = 35; mean age: 11.4 +/- 4.7 years; range: 0.1-17.4 years; 51% male) had supraventricular tachycardia (SVT). No other significant arrhythmia that may warrant treatment was identified. All patients with SVT had palpitations. No patients with isolated chest discomfort, presyncope, or syncope had SVT (N = 75). SVT was documented more frequently in patients with postevent (N = 35/464) than loop recorders (N = 0/31). Of those with SVT, 71% (N = 25) and 91% (N = 33) transmitted events within 4 and 16 weeks, respectively. Follow-up for 1 to 108 months (mean: 32 +/- 25; median: 26) in 53% (243 of 460) of patients without SVT uncovered a 3% (N = 7) rate of subsequent SVT detection. The overall sensitivity of the TTM test was 83% (35 of 42) for detection of SVT. The sensitivity of studies theoretically limited to 4 and 16 weeks would be 60% (25 of 42) and 79% (33 of 42), respectively. The negative predictive value of the TTM study was 99% in our patient population. The negative predictive value of tests theoretically limited to 4 and 16 weeks would be 96% and 98%, respectively. TTM studies of 2 weeks' duration were most cost-effective in terms of total diagnostic yield. In contrast, studies of 4 weeks' duration were most cost-efficient for SVT detection. CONCLUSIONS: TTMs are useful for the evaluation of children and adolescents with palpitations but not with isolated chest pain, syncope, or presyncope. In this study, girls were more likely to transmit events. The sensitivity of TTMs for detection of SVT was 83%. The negative predictive value of the TTM test was 99%. Monitoring for longer than 16 weeks did not increase test sensitivity. Studies of 4 weeks' duration proved most cost-effective for SVT detection.