Epicardial access for mapping and ablation of the epicardial substrate may be required in catheter ablation of ventricular tachycardias (VT). However, high complication rates are associated with the standard epicardial access approach. Recently, a novel method of intentional coronary vein (CV) exit with pericardial CO₂ insufflation to facilitate epicardial access has been described. This study describes our initial experience with this technique.

Patients undergoing epicardial VT ablation between 1 February 2021 to 31 May 2022 at the Royal Prince Alfred Hospital, Sydney, NSW, were included in this study. Via femoral venous access, a branch of the coronary sinus was sub-selected and intentional CV exit was performed with a high tip load coronary angioplasty wire. A microcatheter was then advanced over the wire into the pericardial space, followed by pericardial CO₂ insufflation, facilitating subxiphoid pericardial puncture.

Five (5) patients underwent epicardial access for VT mapping and ablation. All patients had successful intentional CV exit and CO₂ facilitated epicardial access. The mean time to successful epicardial access was 37.2±17.5 minutes. With increasing operator experience, there was improvement in epicardial access times, with the fifth case requiring only 13 minutes. There was one case of inadvertent right ventricular puncture (without haemodynamic or ventilatory compromise) due to inappropriate CO₂ insufflation into the right ventricle. Epicardial access was successful on the second attempt.

This is the first case series of epicardial access facilitated by CO₂ insufflation in Australia. This technique enabled successful epicardial access in all patients in our early experience, with no adverse outcomes from epicardial access. With increasing operator experience, this technique may allow for more widespread adoption of up-front epicardial access for the treatment of VT.