Pulsed field ablation of cardiac arrhythmia

Pulsed field ablation of cardiac arrhythmia

Commonest form of ablation of cardiac arrhythmias uses radiofrequency current delivered through a catheter to produce localised tissue heating and damage of the arrhythmic circuit. Pulsed-field ablation is a novel modality which employs a train of microsecond duration high amplitude electrical pulses that ablate myocardium by electroporation of the sarcolemmal membrane without measurable tissue heating. The ablation pulse waveform has multiple variable components that affect ablation efficacy and is different for different equipment [1].

Success of pulse field ablation depends on the proximity of the electrode to the target tissue, though not necessarily on contact. An important feature of pulse field ablation is its tissue specificity. While myocardium is susceptible to irreversible injury, esophagus, phrenic nerves, pulmonary veins and coronary arteries are relatively resistant. This improves the safety during ablation of atrial fibrillation by preventing collateral damage. Procedure time is reduced due to the rapid achievement of pulmonary vein isolation.

Three multicenter studies evaluating pulse wave ablation were reported in 2021. They are IMPULSE (A Safety and Feasibility Study of the IOWA Approach Endocardial Ablation System to Treat Atrial Fibrillation), PEFCAT (A Safety and Feasibility Study of the FARAPULSE Endocardial Ablation System to Treat Paroxysmal Atrial Fibrillation), and PEFCAT II (Expanded Safety and Feasibility Study of the FARAPULSE Endocardial Multi Ablation System to Treat Paroxysmal Atrial Fibrillation). In these studies, patients with paroxysmal atrial fibrillation underwent pulmonary vein isolation using a basket or flower pulse field ablation catheter [2].

Acute success of pulmonary vein isolation was achieved in all the 121 patients. Pulmonary vein remapping performed in 110 patients at a mean period of 93 days showed durable pulmonary vein isolation in 84.8% of patients. Two patients had pericardial effusions or tamponade and one had hematoma. Mean one year estimated freedom from atrial arrhythmia for the entire cohort was 78.5%. It was 84.5% for optimized biphasic energy.

References

1. Bradley CJ, Haines DE. Pulsed field ablation for pulmonary vein isolation in the treatment of atrial fibrillation. J Cardiovasc Electrophysiol. 2020 Aug;31(8):2136-2147. doi: 10.1111/jce.14414. Epub 2020 May 16. PMID: 32107812.
2. Reddy VY, Dukkipati SR, Neuzil P, Anic A, Petru J, Funasako M, Cochet H, Minami K, Breskovic T, Sikiric I, Sediva L, Chovanec M, Koruth J, Jais P. Pulsed Field Ablation of Paroxysmal Atrial Fibrillation: 1-Year Outcomes of IMPULSE, PEFCAT, and PEFCAT II. JACC Clin Electrophysiol. 2021 May;7(5):614-627. doi: 10.1016/j.jacep.2021.02.014. Epub 2021 Apr 28. PMID: 33933412.