CARDIOVERSION OF ATRIAL-FIBRILLATION IN THE SETTING OF MILD-TO-MODERATE HEART-FAILURE

We investigated the effect of electrical cardioversion of atrial fibri llation in patients with heart failure. The study group consisted of 2 4 patients with mild to moderate heart failure [13 men, mean age 67+/- 7 years, mean peak oxygen consumption (peak VO2) 16.3+/-2.8 ml/min/kg] and chronic atrial fibrillation (median duration 19 (1-228) months). Patients were stable on digoxin, diuretics, nitrates and angiotensin c onverting enzyme inhibitors; no prophylaxis with antiarrhythmics was s tarted after cardioversion. Cardioversion was unsuccessful in 6 patien ts; of the 18 patients in whom sinus rhythm was obtained 9 had a relap se of atrial fibrillation within 6 weeks after cardioversion. The rema ining 9 patients with maintenance of sinus rhythm and the 15 (6+9) pat ients with atrial fibrillation at follow-up after 6 weeks did not diff er with respect to any baseline characteristic, including age, peak VO 2, duration of atrial fibrillation, echocardiographic left ventricular and left atrial dimensions, plasma atrial natriuretic peptide and nor epinephrine. In the patients with maintenance of sinus rhythm, baselin e measurements were repeated at follow-up. Peak VO2 did not change sig nificantly (16.7+/-2.8 to 17.6+/-3.3 ml/min/kg, P=0.29); also, echo pa rameters, atrial natriuretic peptide and norepinephrine were not signi ficantly affected. These results indicate that it is difficult to achi eve lasting sinus rhythm through electrical cardioversion in patients with atrial fibrillation and mild to moderate heart failure. Moreover, in patients with maintenance of sinus rhythm after cardioversion no s ignificant benefit in terms of peak VO2, cardiac dimensions, and neuro humoral status is to be expected. Hence, indiscriminate cardioversion of atrial fibrillation in the setting of heart failure does not appear to be useful. (C) 1998 Elsevier Science Ireland Ltd.