Assessment of upgrading to biventricular pacing in patients with right ventricular pacing and congestive heart failure after atrioventricular junctional ablation for chronic atrial fibrillation

AIMS: Effects of cardiac resynchronization therapy (CRT) in patients with right ventricular pacing and congestive heart failure (CHF) have only been reported in limited series. CRT in patients with atrial fibrillation remains controversial. Patients with AV junctional ablation offer a unique opportunity to study the effects of CRT in patients with right ventricular pacing combined with atrial fibrillation. The aims of the present study were to evaluate the effects of upgrading to biventricular pacing patients with CHF, permanent atrial fibrillation, and prior ablation of the atrioventricular (AV) junction followed by conventional right ventricular pacing. METHODS AND RESULTS: We studied 16 consecutive patients with permanent atrial fibrillation treated by AV junctional ablation. After a mean follow-up of 20+/-19 months (6 weeks to 5 years) they were successfully upgraded to biventricular pacing for severe CHF. Parameters were prospectively evaluated at baseline and at 6 months. The 14 surviving patients at 6 months demonstrated significant improvement (P<0.02) in New York Heart Association class but the exercise test parameters remained unchanged. Cardiothoracic ratio decreased by 5% (P=0.04), end-systolic diameter by 8% (P=0.001), end-diastolic diameter by 4% (P=0.08), systolic pulmonary artery pressure by 17% (P<0.0001) and mitral regurgitation area by 40% (P<0.05). Ejection fraction increased by 17% (P=0.11) and fractional shortening by 24% (P=0.01). CONCLUSION: CRT improves left ventricular performance and functional status in patients with permanent atrial fibrillation and prior remote right ventricular pacing.