Myocardial Lesion Size after Epicardial Electroporation Catheter Ablation following Subxiphoid Puncture
Background—Irreversible electroporation is a promising non-thermal ablation modality able to create deep myocardial lesions. We investigated lesion size after epicardial electroporation catheter ablation with various energy levels following subxiphoid pericardial puncture.
Methods and Results—In 6 six-month-old pigs (60-75 kg), a custom deflectable octopolar 12 mm circular catheter with 2 mm ring electrodes was introduced via a deflectable sheath after pericardial access by subxiphoid puncture. Non-arcing, non-barotraumatic, cathodal 50, 100 and 200-joule (J) electroporation applications were randomly delivered on the basal, mid and lateral left ventricle. After 3 months survival, myocardial lesion size and degree of intimal hyperplasia of the coronary arteries was histologically analyzed. Five animals survived the follow-up without complications, 1 animal died of shock after the subxiphoid puncture. At autopsy, whitish circular scars with indentation of the epicardium could be identified. Average lesion depth of the 50J, 100J and 200J lesions were 5.0 ± 2.1 mm, 7.0 ± 2.0 mm and 11.9 ± 1.5 mm, respectively. Average lesion width of the 50J, 100J and 200J lesions were 16.6 ± 1.1 mm, 16.2 ± 4.3 mm and 19.8 ± 1.8 mm, respectively. In the 100J and 200J cross-sections, transmural left ventricular lesions and significant tissue shrinkage was observed. No intimal hyperplasia of the coronary arteries was observed.
Conclusions—Epicardial electroporation ablation following subxiphoid pericardial puncture can create deep, wide and transmural ventricular myocardial lesions. There is a significant relationship between the amounts of electroporation energy delivered epicardially and lesion size in the absence of major adverse events.
- Received March 10, 2014.
- Revision received June 5, 2014.
- Accepted June 11, 2014.