Implantable atrial defibrillator prevented atrial stunning and improved ventricular funciton after cardioversion from atrial fibrillation

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Successful pulmonary vein isolation using transvenous catheter cryoablation improves quality-of-life in patients with atrial fibrillation

Background: Recent studies have demonstrated that transvenous catheter cryoablation is a safe and effective technique for creating pulmonary veins (PVs) electrical isolation for the treatment of atrial fibrillation (AF). However, the impacts of this procedure on quality-of-life (QoL) have not been evaluated. Methods and Results: We studied the effects of PV isolation using transvenous catheter cryoablation on QoL in 46 patients (34 men, mean age: 50 ± 12 years) with drug-refractory AF. QoL was assessed by Medical Outcomes Study Short Form-36 (SF-36) and Symptom Checklist at baseline and 3-month after cryoablation, and compared with those in a sex-age matched normal control. At 3-month follow-up, 24 of 46 patients (52%) had no recurrence of AF, including 11 patients who were not taking antiarrhythmic drugs. At baseline, patients with AF had significantly lower QoL scores in overall and in 5/8 subscales of SF-36 than the sex-age matched control group (P 0.05). The Symptom Checklist also showed significant reduction in both the symptoms frequency scores and symptoms severity scores at 3-month follow-up as compared with baseline (P < 0.05). Conclusions: Successful PV isolation using transvenous catheter cryoablation is associated with significant reduction in the frequency and severity of AF symptoms and improvement in the general QoL, reaching the levels of normal controls.link_to_subscribed_fulltex

Incremental benefit of rate adaptive pacing on exercise performance during cardiac resynchronization therapy

Poster 2: no. P2-101BACKGROUND: Cardiac resynchronization therapy (CRT) improves exercise capacity in patients (pts) with left bundle branch block (LBBB) and heart failure. However, pharmacologic treatment with -blockers and/or coexisting chronotropic incompetence frequently limit an increase in heart rate during exercise in pts with heart failure, which may have negative effect on the exercise capacity. The potential incremental benefits of using rate adaptive sensor and atrioventricular interval (AVI) adaptation in CRT during exercise have not been studied. METHODS AND RESULTS: We studied the exercise performance in 21 pts (15 males, mean age: 70 9 years) with LBBB (mean QRS duration 176 22 ms) and heart failure (76% nonischemic cardiomyopathy, mean ejection fraction: 24 10%) implanted with CRT for 12 months. All pts received stable medications (86% on -blockers) and their device AVI was optimized by using Ritter’s formula (mean 101 21 ms). All pts underwent cardiopulmonary exercise treadmill test with their pacemaker programmed to 1) DDD mode with fixed AVI (DDD-off); 2) DDD mode with adaptive AVI algorithm on (DDD-on) and 3) DDDR mode with adaptive AVI algorithm on (DDDR-on) in a randomized fashion. The minimum AVI was 76 11 ms using adaptive AVI algorithm at the maximum exercise heart rate. The maximum heart rate achieved during peak exercise was significantly higher with DDDR-on mode than DDD-off and DDD-on mode (Figure 1). Both DDD-on and DDDR-on mode increased the exercise time compared to DDD-off mode (Figure 2). However, the use of DDDR-on mode further increased peak oxygen consumption (VO2 max) compared to DDD-off and DDD-on mode (Figure 3). CONCLUSIONS: In heart failure pts implanted with CRT, the use of rate adaptive pacing and adaptive AVI algorithm can further enhance their exercise performance by reducing chronotropic incompetence during exercise