Predictors of successful catheter ablation of ventricular arrhythmias arising from the papillary muscles.

Background: Ablation of arrhythmias arising from the papillary muscles (PAPs) is challenging.
Objective: The purpose of this study was to assess the predictors of successful catheter ablation in patients with ventricular arrhythmias arising from the PAPs.
Methods: Forty consecutive patients (15 women, mean age 51 ± 14 years, left ventricular ejection fraction 0.46 ± 0.13) with refractory PAP arrhythmias underwent mapping and ablation. Catheter stability was assessed with intracardiac echocardiography. Activation mapping and/or pace mapping were performed to identify the site of origin. Electrophysiological data and anatomic characteristics were assessed in patients with effective versus ineffective ablation. Catheter stability was assessed with intracardiac echocardiography.
Results: Radiofrequency ablation was acutely effective in eliminating the targeted arrhythmia in 31 patients (78%). The presence of Purkinje potentials at the site of origin of the targeted arrhythmia was associated with an effective outcome (48% vs. 0%; P = .01). The mass of the arrhythmogenic PAPs in the left ventricle was significantly larger in patients with failed versus effective ablation (4.7 ± 2.2 g vs. 2.3 ± 0.6 g; P < .0001). Also, the presence of a matching pace map at the earliest endocardial activation time was associated with an effective procedure (71% vs. 22%; P = .02)
Conclusion: The presence of Purkinje potentials at the site of origin and a smaller size of the PAP are associated with successful ablation of PAP arrhythmias.
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