Implantable cardioverter-defibrillator therapy to reduce sudden cardiac death in adults with congenital heart disease: A registry study.

INTRODUCTION: The adult congenital heart disease (ACHD) population is rapidly expanding. However, a significant proportion of these patients suffer sudden cardiac death. Recommending implantable cardioverter-defibrillator (ICD) insertion requires balancing the need for appropriate therapy in malignant arrhythmia against the consequences of inappropriate therapy and procedural complications. Here we present long-term follow-up data for ICD insertion in patients with ACHD from a large Level 1 congenital cardiac center. METHODS AND RESULTS: All patients with ACHD undergoing ICD insertion over an 18-year period were identified. Data were extracted for baseline characteristics including demographics, initial diagnosis, ventricular function, relevant medication, and indication for ICD insertion. Details regarding device insertion were gathered along with follow-up data including appropriate and inappropriate therapy and complications. A total of 136 ICDs were implanted during this period: 79 for primary and 57 for secondary prevention. The most common congenital cardiac conditions in both groups were tetralogy of Fallot and transposition of the great arteries. Twenty-two individuals in the primary prevention group received appropriate antitachycardia pacing (ATP), 14 underwent appropriate cardioversion, 17 received inappropriate ATP, and 15 received inappropriate cardioversion. In the secondary prevention group, 18 individuals received appropriate ATP, 8 underwent appropriate cardioversion, 8 received inappropriate ATP, and 7 were inappropriately cardioverted. Our data demonstrate low complication rates, particularly with leads without advisories. CONCLUSION: ICD insertion in the ACHD population involves a careful balance of the risks and benefits. Our data show a significant proportion of patients receiving appropriate therapy indicating that ICDs were inserted appropriately.

Implantable cardioverter-defibrillator therapy in adult patients with tetralogy of Fallot.

AIMS: Adults with repaired tetralogy of Fallot (TOF) are at risk of sudden cardiac death (SCD). ESC and AHA guidelines suggest the use of implantable cardioverter defibrillators (ICDs) to protect from this. Few data are available on the benefits of these devices in this population, and there are no randomized studies. METHODS AND RESULTS: We analysed outcomes with respect to death, ICD therapy delivery, and complications for 20 patients with repaired TOF and 39 dilated cardiomyopathy (DCM) patients followed up at a UK teaching hospital. All TOF patients had clinical ventricular tachycardia (VT), electrophysiological study-inducible VT, or previous arrest due to tachyarrhythmia and received dual-chamber devices with individualized atrial detection algorithms. Tetralogy of Fallot patients were younger than DCM patients, but follow-up duration was not different between the groups. Tetralogy of Fallot patients were more likely to have experienced oversensing (45 vs. 13%; P < 0.02), inappropriate anti-tachycardia pacing delivery (20 vs. 2%; P < 0.05), and inappropriate cardioversion (25 vs. 4%; P = 0.06) than DCM patients and less likely to receive appropriate therapies than DCM patients. The death rate in TOF patients was significantly lower than that in DCM patients (5 vs. 21%; P < 0.05). CONCLUSION: Tetralogy of Fallot patients have a higher risk of inappropriate therapies and other complications yet a lower incidence of appropriate therapies from their ICD than DCM patients. Further research into identification of factors predicting SCD in TOF and the benefits of ICD implantation is essential given the potential complications of ICD implantation in young congenital heart disease patients.

New outpatient referrals to a tertiary paediatric cardiac centre: evidence of increasing workload and evolving patterns of referral.

OBJECTIVES: To assess the volume and range of diagnosis in new patients referred to paediatric cardiac outpatient clinics. METHODS: Data was collected prospectively, using a proforma completed at all outpatient clinics over a period of three months. RESULTS: There were 526 new referrals, representing an increase of almost one-fifth compared to 5 years ago. Of the referrals, 78 percent came from hospital doctors, and 22 percent from general practitioners, with 221 of those referred being infants. A heart murmur was the most common reason for referral, representing almost two-thirds of cases. In 372 patients referred (71 percent), the heart was discovered to be structurally normal. The proportion of patients with normal hearts referred by general practitioners and hospital doctors were 81 percent, and 68 percent, respectively (p less than 0.004). There was considerable variation in the pattern of referral between doctors working in different hospitals. CONCLUSION: New referrals to centres dealing with congenital cardiac malformations are increasing alarmingly, with the majority of the children referred having normal hearts. This increase in demand for specialist services has important implications for resources and training.

Pacing activity, patient and lead survival over 20 years of permanent epicardial pacing in children.

BACKGROUND: We report on pediatric epicardial pacing activity, patient and lead survival for more than two decades in a single center. METHODS: The data cover 96 pacing leads implanted in 59 patients. Median age at implantation was 1.9 years (1 day to 18.2 years). Forty-four percent had structural cardiac disease. Most frequent indications for pacing were postoperative (42%) and congenital complete heart block (42%). RESULTS: Median activity was 3 pacing leads per year; 326 patient pacing years were observed (median 11.9 years; range, 1.1 to 22 years). Death due to pacemaker failure occurred in a single patient. Lead failure occurred in 33 of 96 leads (median of 28 months postimplantation) with lead fracture the commonest cause (47%). Risk factors for lead failure were decade of implant and nonsteroid eluting leads. Acute implant energy thresholds were significantly lower for steroid than nonsteroid eluting leads but did not predict subsequent lead failure. CONCLUSIONS: The epicardial approach has offered an effective solution to pacing problems in the pediatric age range. Lead survival has improved with more than 75% of modern steroid eluting leads surviving to 5 years.