MP-453081-7 A COMPARISON OF LEFT CIRCUMFLEX CORONARY VASOSPASM BETWEEN RADIOFREQUENCY ABLATION AND PULSED FIELD ABLATION AT THE MITRAL ISTHMUS

Pulsed field ablation (PFA) is a nonthermal energy modality that largely spares collateral structures like the esophagus and phrenic nerve. However, recent study indicates subclinical coronary artery vasospasm common during PFA of cavo-tricuspid isthmus. There also case report left circumflex (LCx) at mitral isthmus (MI). To determine frequency LCx on lateral MI compare to RFA. In prospective, consecutively enrolled cohort patients undergoing AF under deep sedation, diagnostic angiography was performed via right femoral arterial access before, during, after endocardial with either catheter (Farawave, Boston Scientific Inc) or an irrigated RFA (Thermocool, Biosense-Webster Inc). When identified angiography, it monitored for clinical remission hemodynamic changes intervention nitroglycerin administered if refractory upfront supportive care. A total 19 received acute bidirectional block: 11 along superior (1-2 o’clock annulus) 8 inferior (3-5 annulus). total, 7 experienced (2 mild, 3 moderate, 1 severe). By site, (64%) 0 (0%) were MI, respectively. comparison, 9 underwent (all sinus lesions in patients), which there no instances spasm. Of note, 5 due absence block first pass RFA; these did demonstrate spasm PFA. none any symptoms compromise. ECG seen patient: ST elevations severe While confers important degree tissue preferentiality enhanced safety compared thermal esophageal/phrenic damage pulmonary vein stenosis, our data indicate can cause reversible (mostly) ablation. Vasospasm occurred while not spasm; this may be related proximity its superior-inferior course. Conversely, does appear associated significant risk