No abstract

Background-Tetralogy of Fallot is the most common form of congenital heart disease in implantable cardioverterdefibrillator (ICD) recipients, yet little is known about the value of ICDs in this patient population. Methods and Results-We conducted a multicenter cohort study in high-risk patients with Tetralogy of Fallot to determine actuarial rates of ICD discharges, identify risk factors, and characterize ICD-related complications. A total of 121 patients (median age 33.3 years; 59.5% male) were enrolled from 11 sites and followed up for a median of 3.7 years. ICDs were implanted for primary prevention in 68 patients (56.2%) and for secondary prevention in 53 (43.8%), defined by clinical sustained ventricular tachyarrhythmia or resuscitated sudden death. Overall, 37 patients (30.6%) received at least 1 appropriate and effective ICD discharge, with a median ventricular tachyarrhythmia rate of 213 bpm. Annual actuarial rates of appropriate ICD shocks were 7.7% and 9.8% in primary and secondary prevention, respectively (Pϭ0.11). A higher left ventricular end-diastolic pressure (hazard ratio 1.3 per mm Hg, Pϭ0.004) and nonsustained ventricular tachycardia (hazard ratio 3.7, Pϭ0.023) independently predicted appropriate ICD shocks in primary prevention. Inappropriate shocks occurred in 5.8% of patients yearly. Additionally, 36 patients (29.8%) experienced complications, of which 6 (5.0%) were acute, 25 (20.7%) were late lead-related, and 7 (5.8%) were late generator-related complications. Nine patients died during follow-up, which corresponds to an actuarial annual mortality rate of 2.2%, which did not differ between the primary and secondary prevention groups. Conclusions-Patients with tetralogy of Fallot and ICDs for primary and secondary prevention experience high rates of appropriate and effective shocks; however, inappropriate shocks and late lead-related complications are common.

Ongoing loss of sinus rhythm and late peaks in the risk of atrial flutter and death necessitate continued follow-up.

Background-Sudden cardiac death (SCD) is a major cause of mortality in adults with congenital heart disease (CHD).The aim of this study was to determine the adult CHD population at risk of SCD and the clinical parameters associated with SCD. Methods and Results-We performed a multicenter case-control study. Patients who died suddenly as a result of proven or presumed arrhythmia were included (cases