[Radiofrequency ablation of left premature ventricular complex from the papillary muscle]

Radiofrequency ablation for incessant and symptomatic premature ventricular complex (PVC) localized in a left papillary muscle is uncommon. 3D mapping and cardiac MRI may be useful to achieve ablation success.

A fifty-four-years-old man was referred for palpitations. His medical history included placement of a right coronary artery stent six years before and a normal ejection fraction (EF). The Holter monitoring under beta-blocker therapy (46% PVCs) and ECG showed monomorphic PVCs with a right bundle branch block, positive concordance with V5 transition and a superior axis, with no R/T phenomenon. During two separate electrophysiologic procedures (recurrence), a 3D mapping (Velocity, ST-Jude Medical™) system was used combined with an irrigated tip catheter. The earliest site of PVC activation documented with the mapping system was near the posterior papillary muscle. Pace mapping in this area showed nearly 90% concordance. After 2126 seconds of radiofrequency applications, there were no more PVC and no inducible arrhythmia. Post procedure cardiac MRI showed scar in the inferior-lateral area of the left ventricle including a section of the posterior papillary muscle. Scar included 50% of the thickness of the wall (previous 2005 myocardial infarction and radiofrequency lesions). Residual EF was 55%. At 2 months of follow-up, the patient was asymptomatic, with only 53 PVCs on 24-hour Holter monitoring. Patient was maintained under beta-blocker therapy for his coronary artery disease. At six-month follow-up, he is still asymptomatic.

This case report stresses the role of cardiac MRI and 3D cartography systems for successful treatment of papillary muscle PVCs associated with ischemic cardiomyopathy, which still represent a therapeutic challenge.