Characteristics and Long-Term Outcomes of Patients with Left Ventricular Papillary Muscle Arrhythmias

Abstract

Background: Ventricular arrhythmias (VAs) can originate from the left ventricular (LV) papillary muscles (PMs). In addition to causing potentially debilitating symptoms, VAs can cause significant left ventricular (LV) dysfunction. Methods: 185 patients had PVCs activation and pace mapped to the LV PMs. The clinical characteristics, aetiology and outcomes of patients were investigated. Results: At baseline, 76 (41%) had normal LVEF and 109 (59%) low LVEF (mean LVEF 30.5 ± 10.5%). PM VAs were PVCs in 123 (67%) and non-sustained VT in 61 pts (33%). Site of origin was the LV postero-medial PM in 106 (57%) and LV antero-lateral PM in 69 (37%) and both PMs in 10 pts (6%). 140 pts (76%) had idiopathic VAs and in 45 pts (24%) the site of origin of VA was confined to endocardial scar tissue. Acute success was achieved in 91% of patients. During the 65 ± 37 months of follow-up, VA free survival was 85% after a single procedure and 93% after repeat procedure. On multivariate analysis, presence of structural heart disease (HR 2.16 CI: 1.4 to 3.9 p = 006) and number of distinct PVC morphology (HR 1.5 CI: CI: 1.2 to 1.9 p = 0.02) were independent predictors of VA recurrence. After successful ablation, in pts with idiopathic VA, the mean LV ejection fraction improved from 29.7 ± 12.5% to 53.1 ± 2.5% vs. 30.5 ± 11.3% to 45.1 ± 6.5% in scar related VAs (p = 0.02). Conclusion: Catheter ablation of frequent VAs is a low-risk and effective treatment strategy.