[Effect of oral long-term enoximone therapy on the arrhythmia profile in chronic heart failure]

The arrhythmogenic potential of long-term treatment with Enoximone in patients with severe chronic heart failure has not been determined. We analysed retrospectively 24 h Holter recordings in 31 patients with chronic heart failure, predominantly NYHA functional class III and IV, before and during chronic Enoximone therapy between 4 and 52 weeks. At baseline ventricular couplets and salvos were found in 68% of patients. Ventricular arrhythmia response was variable with no significant overall change. During a mean follow-up of 28 weeks, however, 3 (10%) patients showed a significant increase and 4 (16%) patients a more than 90% decrease of repetitive ventricular arrhythmias. In another 10 (32%) patients a more than 70% decrease of singular ventricular arrhythmias was observed. There was no correlation between the change of the patient's arrhythmia profile, the degree of functional impairment of the underlying heart disease, and the clinical response to long-term Enoximone therapy. Two patients died suddenly, one with a significant increase, the other with a significant reduction of ventricular arrhythmias. Two patients died of pump failure with no change of the arrhythmia profile. Enoximone appears to have a low arrhythmogenic profile during long-term treatment. However, careful monitoring of ventricular arrhythmias is mandatory as the occurrence of proarrhythmic drug effects cannot be predicted.