Acute success of focal pulsed field ablation for the treatment of premature ventricular outflow tract contractions

Radiofrequency ablation of outflow (OT) of premature ventricular contractions (PVC) is well established and showed satisfactory acute success with reasonable long term recurrence rates. There is little data regarding PVCs ablation using pulsed field energy. Due to increased transmurality, pulsed field ablation (PFA) may have an advantage in cases of mid- and epimyocardial origins, yet proximity to the coronary arteries may increase the risk of PFA related vasospasms.

To assess safety and acute efficacy of focal PFA for OT PVCs

A prospective cohort of 35 patients referred for PVC ablation was enrolled. All procedures were performed using the CENTAURI™ System in combination with contact-force sensing catheters and 3D-electroanatomic mapping systems. Acute success was defined as ≥ 80% reduction of the PVC burden during a 24h in-hospital continuous ECG monitoring period.

Patients (median age: 65 (IQR: 56, 73) years, 69% males) presented with symptomatic monomorphic (72,5%) or pleomorphic PVCs with a main morphology arising from the OT (28,5%). Acute success was achieved in 88% (31/35) of the cases. The ablation target side was left sided in 60% of the cases, ablation in both ventricles was performed in 31%. The median procedural time was 120 (IQR 90,145) minutes. All procedures were performed fluoroless, unless a coronary angiogram was needed to locate the coronary arteries before ablation in the anterior interventricular vein. On average, eleven applications were delivered to the site of origin. Three of the patients who experienced acute recurrence had a left ventricular origin of their PVCs, while one patient had recurrence of RVOT PVCs. All patients received intravenous (i.v.) nitroglycerine before energy application. In three cases, additional epicardial ablation in the anterior interventricular vein was required, in one patient this additional ablation resulted in acute cessation of the PVCs, while the other two had acute recurrences. During an ablation attempt in the anterior interventricular vein, severe spasm of the left anterior descending artery ensued which quickly recovered after additional administration of i.v. nitroglycerine. No additional complications were encountered.

Focal PFA is feasible and quite successful in a cohort of symptomatic patients with OT PVCs. Coronary vasospasm is a possible complication despite nitroglycerine application.