Benefits of Cardiac Resynchronization Therapy in Patients With Atrial Fibrillation Who Have Not Undergone Atrioventricular Node Ablation

The aim of this study was to compare the effects of cardiac resynchronization therapy on left ventricular function and reverse remodeling in patients in sinus rhythm with the effects in patients with atrial fibrillation who have not undergone atrioventricular node ablation. Echocardiographic and clinical parameters were evaluated at baseline and after 6 months of cardiac resynchronization therapy in 55 patients: 15 had atrial fibrillation and 40 were in sinus rhythm. Device programming was similar in the 2 groups, as were the reductions in QRS interval and echocardiographic measures of asynchrony observed after implantation. However, although significant improvements in end-systolic volume and ejection fraction were seen in both groups, reverse remodeling was greater in patients in sinus rhythm (reduction in end-systolic volume 30.9% [24.6%] vs 12.5% [18.6%]; ft.024), as was the relative increase in ejection fraction (15.4% [12.6%] vs 5.0% [7.2%]; fk010). Cardiac resynchronization therapy in patients with atrial fibrillation who had not undergone atrioventricular node ablation resulted in significant improvements in ejection fraction and reverse remodeling, but these were less than those observed in patients in sinus rhythm.

El objetivo fue comparar el efecto de la terapia de resincronizacion cardiaca en la funcion ventricular y el re-modelado inverso en pacientes en ritmo sinusal y fibrilacion auricular sin ablacion del nodulo auriculoventricular. Se analizaron parametros clínicos y ecocardiograficos antes y 6 meses tras la resincronizacion de 55 pacientes: 15 en fibrilacion auricular y 40 en ritmo sinusal. La pro-gramacion del dispositivo, el estrechamiento del QRS y la asincronia ecocardiografica tras el implante fueron simila-res en ambos grupos. Sin embargo, aunque en ambos grupos se observo mejoria significativa del volumen tele-sistolico y la fraccion de eyeccion, los pacientes en ritmo sinusal presentaron mayor remodelado inverso (reduc-cion del volumen telesistolico del 30,9% ± 24,6% contra el 12,5% ± 18,6%; p = 0,024) y aumento relativo en la fraccion de eyeccion (el 15,4% ± 12,6% y el 5% ± 7,2%; p = 0,010). La terapia de resincronizacion en pacientes con fibrilacion auricular sin ablacion del nodulo mejora significativamente la fraccion de eyeccion y el remodelado inverso, pero menos que en ritmo sinusal.