Permanent Atrial Fibrillation Affects Exercise Capacity in Chronic Heart Failure Patients

Title: Permanent Atrial Fibrillation Affects Exercise Capacity in Chronic Heart Failure Patients

Author(s): Agostoni P, Emdin M, Corra U, et al.

Citation: Eur Heart J 2008;Aug 5:[Epub ahead of print].

Clinical Trial: No

Study Question: Does atrial fibrillation (AF) have a negative impact on exercise tolerance in patients with heart failure (HF)?
Methods: This was a retrospective analysis of 942 patients with HF who underwent cardiopulmonary exercise testing (CPET). Patients were categorized by the presence (n = 180) or absence (n = 762) of permanent AF, defined as AF present continuously for >1 year.

Results: Peak heart rate was significantly higher in the AF group (136 vs. 125 bpm). Peak oxygen consumption (VO2) was significantly lower in the AF group (1024 vs. 1156 ml/min/kg), as were several other CPET parameters. When corrected for age, gender, and ejection fraction, AF still was associated with a lower peak VO2.

Conclusions: In patients with HF, AF significantly impairs exercise performance.

Perspective: There are three potential mechanisms by which AF negatively impacts cardiac performance: an excessive heart rate response to exercise, irregularity of the rhythm, and loss of atrioventricular synchrony. Therefore, it is not surprising that AF compromises exercise performance in patients with HF. A prior study demonstrated that restoration of sinus rhythm by radiofrequency catheter ablation in HF patients with AF resulted in a significant improvement in ejection fraction and decrease in left ventricular diameter, even in patients who had good rate control in AF. The present study, along with this prior study, provides support for a rhythm-control strategy in HF patients with AF. Fred Morady, M.D., F.A.C.C.