Catheter ablation of ventricular arrhythmias originating from the junction of the pulmonary sinus cusp via a nonreversed U curve approach

Abstract

Ventricular arrhythmias (VAs) can originate from the pulmonary sinus cusp, and reversed U curve ablation has been highly efficient treatment. The purpose of this study was to clarify the characteristics of VAs originating from the pulmonary sinus junction (PSJ): left cusp-anterior cusp (LC-AC), right cusp-left cusp (RC-LC), and right cusp-anterior cusp (RC-AC). One hundred twenty-five consecutive patients with right ventricular outflow (RVOT)-type VAs were enrolled in the study and analyzed. Seventeen RVOT-type VAs (13.6%) had an anatomic origin at the PSJ (9 at LC-AC, 6 at RC-LC, 4 at RC-AC). For PSJ-VA patients, the earliest activation site was identified at the PSJ 22.65 ± 2.47 mm above the pulmonary sinus base and preceded QRS onset by 35.7 ± 12.7 ms (P <.001). Fourteen of the 17 PSJ-VA patients underwent successful ablation via a nonreversed U curve after failed reversed U curve ablation. The bipolar proximal potential was earlier, equal to, or later than the distal potential when the reversed U curve catheter tip was positioned at the bottom, middle, or junction region of individual sinus. Electrocardiographic analysis revealed a lower amplitude of RC-AC than LC-AC and RC-LC VAs (P<.001). The PSJ is a nonrare but distinct origin of RVOT-type VAs. The nonreversed U curve approach is a more feasible alternative for PSJ-VAs than the reversed U curve approach.