Premature ventricular complex site of origin and ablation outcomes in patients with prior myocardial infarction

BACKGROUND Frequent premature ventricular complexes (PVCs) are common after a myocardial infarction (MI), but data on PVC ablation in this population are limited.OBJECTIVE The purpose of this study was to analyze data on PVC ablation in post-MI patients.METHODS Three hundred thirty-two patients with frequent PVCs and left ventricular (LV) dysfunction were prospectively studied. Data from 67 patients (20%; age 63 +/- 10 years; 65 men [93%]) with previous MI were compared with the remaining 265 patients.RESULTS PVCs in post-MI patients originate predominantly from the LV (92% LV vs 6% right ventricle [RV]; P <.001). The most frequent sites of origin (S00) were MI scar in 23 patients (34%) and left ventricular outflow tract (LVOT) in 22 patients (33%). A papillary muscle origin was more frequent in post-MI patients (16% vs 4%; P = .001), whereas an RV outflow tract origin was less frequent (1% vs 33%; P < .001) compared to patients without MI. In post-MI patients, PVC burden decreased from 29% +/- 12% at baseline to 4.6% +/- 7% (P <.001); left ventricular ejection fraction (LVEF) improved from 33.6% +/- 8% to 42% +/- 10% (P <.001); and New York Heart Association functional class improved from 2.1 +/- 0.7 to 1.4 +/- 0.5 points (P <. 001) at 12 months. Compared with the remaining 265 patients, there were no differences in acute ablation success (85% vs 85%; P = .45), complication rate (6% vs 6%; P = .41), or absolute improvement in LVEF (8.8 +/- 10 vs 9.9 +/- 11 absolute points; P = .38).CONCLUSION PVC ablation significantly improves cardiac function and functional status in post-MI patients. PVCs predominantly originate from MI scar and LVOT. A papillary muscle SOO was found to be strongly associated with previous MI.