Endocardial ventricular pulsed field ablation: a proof-of-concept preclinical evaluation

Abstract

Aims Pulsed field ablation (PFA) is a novel, non-thermal modality that selectively ablates myocardium with ultra-short electrical impulses while sparing collateral tissues. In a proof-of-concept study, the safety and feasibility of ventricular PFA were assessed using a prototype steerable, endocardial catheter. Methods and results Under general anaesthesia, the left and right ventricles of four healthy swine were ablated using the 12-Fr deflectable PFA catheter and a deflectable sheath guided by electroanatomic mapping. Using the study catheter, electrograms were recorded for each site and pre-ablation and post-ablation pacing thresholds (at 2.0 ms pulse width) were recorded in two of four animals. After euthanasia at 35.5 days, the hearts were submitted for histology. The PFA applications (n = 39) resulted in significant electrogram reduction without ventricular arrhythmias. In ablation sites where it was measured, the pacing thresholds increased by >16.8 mA in the right ventricle (3 sites) and >16.1 mA in the left ventricle (7 sites), with non-capture at maximum amplitude (20 mA) observable in 8 of 10 sites. Gross measurements, available for 28 of 30 ablation sites, revealed average lesion dimensions to be 6.5 ± 1.7 mm deep by 22.6 ± 4.1 mm wide, with a maximum depth and width of 9.4 mm and 28.6 mm, respectively. In the PFA lesions, fibrous tissue homogeneously replaced myocytes with a narrow zone of surrounding myocytolysis and no overlying thrombus. When present, nerve fascicles and vasculature were preserved within surrounding fibrosis. Conclusion We demonstrate that endocardial PFA can be focally delivered using this prototype catheter to create homogeneous, myocardium-specific lesions.

Management of ventricular tachycardia in patients with cardiac sarcoidosis

“… 42 , 50 Pulsed field ablation is an emerging energy source that has the advantage of tissue specificity. 51 Therefore this technology has the potential to address challenges faced in VT ablation. 51 Experimental studies show that pulsed field ablation can achieve transmural ablation lesions without injury to coronary arteries and the risk of collateral damage to adjacent structures (eg, phrenic nerve).…”

Does pulsed field ablation regress over time? A quantitative temporal analysis of pulmonary vein isolation

“…Pulsed field ablation (PFA) is a nonthermal energy modality that is unique in having tissue-selective ablative properties. [1][2][3][4][5][6][7] Using a custom PFA generator able to deliver a custom hierarchical pulse sequence, a dedicated PFA catheter was shown to be safe and effective in electrically isolating porcine thoracic vessels-pulmonary veins (PVs) and superior vena cava. Histological analysis demonstrated similar transmurality to radiofrequency ablation, but without the attendant collateral injury.…”

Fibrilação Atrial (Parte 2) – Ablação por Cateter

“… 109 , 110 Os cardiomiócitos têm um dos limiares de lesão tecidual mais baixos, podendo, por isso, ser aplicados limitando o dano colateral, como o esôfago 111 e o nervo frênico. 112 …”

“… 109 , 110 Cardiomyocytes have one of the lowest tissue injury thresholds, and PFA can therefore be applied during catheter ablation, limiting collateral damage to nearby structures such as the esophagus 111 and phrenic nerve. 112 …”