Feasibility and safety of pulsed field ablation at the ventricular outflow tract using focal point catheter

Ventricular arrhythmias commonly originate from the ventricular outflow tract. It remains unexplored whether pulsed field ablation (PFA) can create durable lesions safely at the ventricular outflow tract. This study aimed to evaluate the feasibility and safety of a novel PFA catheter to deliver focal ablation to the ventricular outflow tract, especially pulmonary and aortic sinus cusps (PSCs and ASCs). Twelve swine were divided into 3 groups: 24-hour, 2-week, and 4-week post-ablation. PFA was delivered to predefined sites of PSCs and ASCs with a focal point catheter, positioned by a mapping system, fluoroscopy, and intracardiac echocardiography. Electrophysiologic assessment, coronary angiography, transesophageal echocardiography, and gross and histologic examination were performed to evaluate the impact of PFA delivery on cardiac structure and function. All subjects survived, and no adverse events were observed. There was a significant decrease in voltage amplitude and increase in pacing thresholds at PSCs and ASCs. There were no significant differences in AH or HV intervals between pre-ablation and post-ablation (AH, P = .70; HV, P = .90). After PFA delivery to ASCs, coronary arteries were fully perfused in each heart, without ST-segment elevation observed. No severe valvular dysfunction was observed on intracardiac echocardiography and transesophageal echocardiography. Gross and histologic examination confirmed the creation of well-demarcated lesions at the targeted sites without damage to adjacent structures. PFA delivered by the focal point catheter could create durable lesions at PSCs and ASCs without damage to coronary arteries, atrioventricular block, or valvular dysfunction, indicative of the feasibility and safety of this novel PFA catheter at the ventricular outflow tract.