Impact of sinus rhythm restoration and maintenance on left ventricular function and exercise tolerance in patients...

Although early improvement of haemodynamic parameters following successful cardioversion of atrial fibrillation (AF) has been well documented, the long-term benefits of sinus rhythm (SR) restoration are less obvious, mainly due to a high rate of AF relapses.

To determine the impact of SR restoration and maintenance on exercise tolerance and heart failure progression in patients with persistent non-valvular AF during a one year follow-up period.

We studied 104 patients (33 females, 71 males, mean age 60.4+/-7.4 years) with mild to moderate stable heart failure and persistent AF with well-controlled ventricular rate who were scheduled for cardioversion. They underwent submaximal exercise testing 24 hours before cardioversion, as well as 1 and 12 months afterwards. Exercise capacity was determined during symptom-limited exercise testing, according to a modified Bruce protocol. Heart failure symptoms were assessed at the same time-points of follow-up.

SR was presented in 66 (63.5%) patients one year after cardioversion. In patients with SR, a significant improvement in left ventricular (LV) performance, exercise capacity and heart failure symptoms was noted. There was an increase in LV fractional shortening (29.9+/-7.6% vs 35.6+/-9.3%; p<0.001), maximal workload (4.7+/-2.3 vs 8.5+/-3.0 MET; p<0.001), exercise duration (125.3+/-115.3 vs 294.7+/-216.7 sec.; p<0.001), and improvement in the NYHA functional class (p<0.001). No such changes were observed in patients who had AF relapse during follow-up or in those who had unsuccessful cardioversion.

Successful cardioversion of persistent AF resulted in a significant improvement of exercise capacity and a decrease in heart failure symptoms during one year follow-up period only in patients who maintained SR.