Arrhythmias and sudden death after dynamic cardiomyoplasty.

BACKGROUND

The main causes of death in patients with severe cardiomyopathy are progressive heart failure and sudden death. The influence of cardiomyoplasty on the incidence of sudden death and arrhythmias in patients with cardiomyopathy remains unclear. The aim of this study was to investigate the occurrence of arrhythmias and sudden death after cardiomyoplasty.

METHODS AND RESULTS

We studied 32 patients (26 male, 6 female; mean age, 48 +/- 12 years) who submitted to cardiomyoplasty for treatment of heart failure in New York Heart Association (NYHA) class III (n = 24) or class IV (n = 8). The etiology was idiopathic dilated cardiomyopathy in 27 patients, ischemic heart disease in 3 patients, and Chagas' heart disease in 2 patients. Patients were routinely studied before and every 6 months after cardiomyoplasty by means of radioisotopic angiography and 24-hour Holter monitor recordings. There were no operative or immediate postoperative deaths. During the postoperative period, 5 patients presented with acute atrial fibrillation and 1 had an episode of sustained ventricular tachycardia. All episodes were successfully treated with intravenous antiarrhythmic drugs or cardioversion. During follow-up (from 2 to 66 months), 15 patients died from sudden death (n = 5) or progressive heart failure (n = 10). Survival rates at 1, 2, and 4 years were 79.9 +/- 7%, 62.5 +/- 9.7% and 35 +/- 12.1%, respectively. At 6-month follow-up, NYHA functional class improved from 3.2 +/- 0.4 to 1.7 +/- 0.6 (P = .001) and left ventricular ejection fraction increased from 19.8 +/- 3.3% to 24 +/- 8.2% (P = .004). The mean values per day of premature ventricular complexes (PVCs) and episodes of nonsustained ventricular tachycardia (NSVT) did not change statistically. The mean number of PVCs per 24 hours before and at 6, 12, 24, 36, and 48 months after surgery were 126 +/- 44, 96 +/- 33, 90 +/- 29, 81 +/- 35, 71 +/- 35, and 59 +/- 48. The mean number of episodes of NSVT per 24 hours before and at 6, 12, 24, 36, and 48 months after surgery were 3.3 +/- 1.3, 1.9 +/- 0.5, 1.3 +/- 0.5, 1 +/- 0.5, 1.5 +/- 1.1, and 0.6 +/- 0.5, respectively. With respect to analysis of the idiopathic dilated cardiomyopathy subgroup, there also were no significant differences in the incidences of pre- and postoperative arrhythmias.

CONCLUSIONS

Despite NYHA functional class and left ventricular function improvements observed after cardiomyoplasty, the incidence of arrhythmias did not change, and sudden death was an important finding mainly in late follow-up. The problem of sudden death after cardiomyoplasty, the mechanism that produces it, and the means to prevent it remain critical areas for future research.