In patients with chronic atrial fibrillation and left ventricular systolicdysfunction, restoration of sinus rhythm confers substantial benefit

Study objectives: To evaluate the benefit of sinus rhythm (SR) restoration in patients with chronic controlled atrial fibrillation (AF) and left ventr icular systolic dysfunction (LVSD). Design: Prospective case-control study on the short-term outcome (6 to 9 mo nths) of clinical and echocardiographic variables following attempted cardi oversion, Setting: Outpatient clinic of a university hospital. Patients: Fifteen men and 5 women, ranging in age from 40 to 76 years, who had chronic controlled (mean [+/- SD] ventricular rate, 82 +/- 10 beats/min ) AF and left ventricular fractional shortening (LVFS) of < 28% at baseline . Control was provided hy retrospective paired echocardiographic examinatio ns of six AF patients, plus the study cases with potentially unsuccessful c ardioversion or early recurrence of AF, Interventions: Attempt to restore SR with amiodarone or electrical counters hock. Measurements and results: Conversion was attained in 17 patients, but AF re curred early in 4 patients, 3 of whom had proven ischemic LVSD. In the 13 p atients with sustained SR, LVFS increased from 20 +/- 4% to 31 +/- 6% (p < 0.0001), In contrast, no changes were detected in the control group (n = 13 ), This improvement was paralleled by decreases in left ventricular (LV) en d-diastolic dimension (from 55 +/- 7 to 51 +/- 6 mm; p = 0.014), LV mass (f rom 181 +/- 28 to 159 +/- 37 g; p = 0.015), and left atrial diameter (from 45 +/- 9 mm to 42 +/- 7; p = 0.003), A marked decrease in heart rate (from 82 +/- 9 to 64 +/- 5 beats/min; p < 0.0001) and a reduction in New York Hea rt Association functional class (from 2.3 +/- 0.9 to 1.2 +/- 0.4; p = 0.000 7) also were observed in patients with sustained SR but not among subjects in the control group, Conclusions: Even when adequate control of the ventricular rate has been ac hieved, tile LV function of patients with chronic AF greatly improves after restoration and maintenance of SR.