The conundrum of ventricular arrhythmia and cardiomyopathy: which abnormality came first?

Ventricular arrhythmia and cardiomyopathy often coexist. Many patients with abnormal ventricular function have either documented premature ventricular contractions (PVCs) or nonsustained ventricular tachycardia and have an increased risk of sudden death from ventricular fibrillation. Tachycardia is a treatable cause of cardiomyopathy. The culprit arrhythmia may be atrial tachycardia, atrial fibrillation, or another supraventricular arrhythmia. The syndrome of PVCs giving rise to ventricular dysfunction was recently described. Thus, a conundrum exists for clinicians in determining which abnormality (PVCs or cardiomyopathy) came first and gave rise to the other. Solving this dilemma is important because radiofrequency ablation for frequent PVCs can completely reverse the cardiomyopathy and normalize systolic ventricular function. In this article, we describe the present evidence for the syndrome of PVCs that can be ablated as a cause for cardiomyopathy. We include a case example and discussion to illustrate this concept and provide a stepwise approach to determining whether PVCs cause cardiomyopathy or vice versa.