Comparative study of nanosecond and microsecond pulsed field ablation for pulmonary vein isolation in preclinical models

Nanosecond pulsed field ablation (nsPFA) has emerged as an alternative in atrial fibrillation (AF) ablation. It leverages the alleviated muscle contractions (MCs) associated with nanosecond pulses, which may reduce complications and anaesthetic requirements compared with conventional microsecond PFA (μsPFA). To pre-clinically compare the safety, efficacy, and MC effects of nsPFA and μsPFA.

Typical parameters were tested for pulmonary vein isolation (PVI) in swine using a novel commercial PFA system with either nsPFA or μsPFA protocols. Procedural outcomes and histological analysis were evaluated at 3-, 30-, and 90-day follow-ups. Electrical stimulation experiments were conducted using various pulse voltages and widths (ranging from nanoseconds to microseconds) to evaluate contractions in swine. nsPFA was non-inferior to μsPFA in terms of PVI safety and efficacy in the follow-up of 18 swine ablation procedures. Both protocols achieved consistent transmural and circumferential lesion creation without damaging adjacent structures such as the oesophagus or causing phrenic nerve block or paralysis. Additionally, nsPFA induced significantly lower MCs than μsPFA did in swine.

The nsPFA protocol is a demonstrated potential approach for AF ablation, demonstrating comparable safety and efficacy to μsPFA, with reduced MCs. These findings suggest that nsPFA may offer an equally effective alternative, with significantly reduced MCs, which may translate to lower anaesthesia requirements.