This patient has frequent, symptomatic premature ventricular contractions (PVCs) with decline in his left ventricular function despite treatment with β-blocker therapy. As there is no clear underlying myocardial process, it is likely that his PVCs may represent a reversible cause of his cardiomyopathy. He should be referred to a cardiac electrophysiologist for catheter ablation of his PVCs.

PVCs are common and are usually benign. However, symptomatic or frequent PVCs (>10,000 PVCs/24 hours or >10% of all beats) require treatment. Up to one third of patients with frequent PVCs develop PVC-induced cardiomyopathy and progressive left ventricular dysfunction. First-line therapy for symptomatic or frequent PVCs is β-blocker or calcium channel blocker therapy. Patients with medically refractory frequent PVCs or who develop left ventricular dysfunction should undergo catheter ablation of the PVCs. Catheter ablation leads to resolution of PVC-induced cardiomyopathy in most patients.

Amiodarone could be used for PVC suppression; however, it has many long-term risks, including thyroid, liver, pulmonary, and neurologic toxicity. Given this patient's relatively young age, amiodarone would not be the most appropriate therapy, particularly if long-term control is needed.

Cardiac resynchronization therapy involves the simultaneous pacing of both ventricles in patients with advanced heart failure and evidence of intraventricular conduction delay (QRS interval ≥150 ms) to reduce dyssynchrony to improve pump performance. This patient does not have severe heart failure or evidence of dyssynchrony. As his symptoms are related more to his ventricular ectopy, cardiac resynchronization therapy would not be appropriate.

An implantable cardioverter-defibrillator (ICD) is indicated in patients at risk for ventricular tachycardia or ventricular fibrillation to prevent sudden cardiac death. Although this patient has very frequent PVCs, including bigeminy, he does not have sustained tachyarrhythmias of potential hemodynamic significance. Therefore, ICD placement would not be appropriate in this patient.