Right Ventricular Pacing Can Induce Ventricular Dyssynchrony in Patients With Atrial Fibrillation After Atrioventricular Node Ablation

ObjectivesThis study was designed to assess the effects of long-term right ventricular (RV) pacing on left ventricular (LV) dyssynchrony, LV function, and heart failure symptoms.BackgroundAtrioventricular (AV) node ablation and subsequent long-term RV pacing is a well-established treatment option in patients with atrial fibrillation (AF).MethodsIn 55 patients with drug-refractory AF, AV node ablation and implantation of a pacemaker was performed. At baseline and after a mean of 3.8 ± 1.7 years, LV dyssynchrony (by M-mode echocardiography and tissue Doppler imaging), LV function, and volumes and functional status were assessed.ResultsAfter long-term RV pacing, 27 patients (49%) had developed LV dyssynchrony. Concomitantly, these patients worsened in heart failure symptoms (New York Heart Association functional class increased from 1.8 ± 0.6 to 2.2 ± 0.7, p < 0.05), with a decrease in LV ejection fraction (from 48 ± 7% to 43 ± 7%, p < 0.05) and an increase in LV end-diastolic volume (from 116 ± 39 ml to 130 ± 52 ml, p < 0.05). Conversely, patients without LV dyssynchrony did not deteriorate in heart failure symptoms, LV function, or LV volumes.ConclusionsLong-term RV pacing can induce LV dyssynchrony in almost 50% of patients treated with AV node ablation for chronic AF. The development of LV dyssynchrony was associated with deterioration in heart failure symptoms, systolic LV function, and LV dilatation.