In patients with chronic atrial fibrillation and left ventricular systolic dysfunction, 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 ventricular systolic dysfunction (LVSD).

DESIGN

Prospective case-control study on the short-term outcome (6 to 9 months) of clinical and echocardiographic variables following attempted cardioversion.

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 by retrospective paired echocardiographic examinations of six AF patients, plus the study cases with potentially unsuccessful cardioversion or early recurrence of AF.

INTERVENTIONS: Attempt to restore SR with amiodarone or electrical countershock.

MEASUREMENTS AND

RESULTS

Conversion was attained in 17 patients, but AF recurred early in 4 patients, 3 of whom had proven ischemic LVSD. In the 13 patients 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) end-diastolic dimension (from 55 +/- 7 to 51 +/- 6 mm; p = 0.014), LV mass (from 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 Heart Association functional class (from 2.3 +/- 0.9 to 1.2 +/- 0.4; p = 0.0007) 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 achieved, the LV function of patients with chronic AF greatly improves after restoration and maintenance of SR.