Pulmonary sinus cusp mapping and ablation: A new concept and approach for idiopathic right ventricular outflow tract arrhythmias.

BACKGROUND: Right ventricular outflow tract (RVOT) ventricular arrhythmias (VAs) may originate from the pulmonary sinus cusps (PSCs) far more frequently than previously recognized.

OBJECTIVE: The purpose of this study was to assess whether mapping and ablation in PSCs might be an appropriate first-choice treatment in unselected patients with idiopathic RVOT VAs.

METHODS: Ninety consecutive patients with VAs of RVOT-type origin were prospectively enrolled at our institution between August 2015 and September 2016. Pulmonary valve (PV) and PSCs were precisely localized by pulmonary arteriography. Activation and pace-mapping were performed in the PSCs and RVOT region below the PV, and ablation was preferentially performed in PSCs.

RESULTS: In 81 patients (90%), earliest activation of VAs was found in PSCs, and ablation resulted in elimination of VAs without any additional ablation in the RVOT region underneath the PV. The best pace-map was obtained at successful ablation sites in PSCs in 96.3% of patients. In the remaining 9 patients, final successful ablation sites were in the aortic coronary cusps in 5 and at the lowest and most posterior part of the RVOT in 4. During mean follow-up of 15.2 ± 9.5 months, single procedural success rate was 96.7%.

CONCLUSION: In this single-center, prospective study, a strategy based on PSC mapping and ablation eliminated 90% (81/90) of unselected idiopathic RVOT-type VAs with favorable mid-term effectiveness.