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.
The effect that aerobic (AT) and/or strength training (ST) has on altering peak aerobic power (VO2peak), muscle strength, left ventricular (LV) morphology, and diastolic filling in healthy older women is not known. We assessed the effects of 12 weeks of AT, ST, combined aerobic and strength training (COMT), or no training (NT) on VO2peak, muscle strength, LV morphology, and diastolic filling in 31 healthy women (68 +/- 4 years). Relative VO2peak was significantly greater after 12 weeks of AT, ST, or COMT. Upper and lower extremity strength were significantly higher after 12 weeks of ST or COMT with no change after AT or NT. LV morphology and diastolic filling were not altered after 12 weeks of AT, ST, COMT, or NT. Twelve weeks of ST or COMT are as effective as 12 weeks of AT for increasing relative VO2peak, however, ST and COMT are more effective than AT for improving overall muscle strength.
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