Suppression of frequent premature ventricular contractions and improvement of left ventricular function in patients with presumed idiopathic dilated cardiomyopathy

Objective: To examine the hypothesis that suppression of frequent premature ventricular contractions may be associated with improvement in left ventricular function in patients with presumed idiopathic dilated cardiomyopathy, Design: We conducted a retrospective case study and statistical analysis of the effect of cardiac medical therapy on outcome. Material and Methods: The study population consisted of 14 patients with more than 20,000 premature ventricular contractions in 24 hours recorded by Holter monitoring and associated left ventricular dysfunction (ejection fraction, 40% or less). Clinical characteristics, number of premature ventricular contractions per hour on 24-hour ambulatory Holter monitoring, and ejection fraction based on transthoracic echocardiography were compared before and after cardiac therapeutic intervention. Results: Of the 14 patients, 10 had presumed idiopathic dilated cardiomyopathy, and 4 had ischemic heart disease. Of the overall study group, seven had received additional cardiac medical therapy after the index evaluation, including four patients who had amiodarone therapy. A significant reduction (75% or more from baseline) in premature ventricular contractions after medical therapeutic intervention was observed in five patients at the first follow-up examination. The mean interval to the first follow-up examination was 6 +/- 3 months. Of the five patients, four had significant improvement in clinical functional status and the ejection fraction. The mean ejection fraction of these five patients increased from 27 +/- 10% at baseline to 49 +/- 17% after medical therapy (P = 0.04). Conclusion: The suppression of frequent premature ventricular contractions may be associated with improvement of left ventricular function in patients with presumed idiopathic dilated cardiomyopathy.