PO-02-095 UTILITY OF LOCAL IMPEDANCE MONITORING TO GUIDE HIGH-POWER SHORT-DURATION RADIOFREQUENCY ABLATION FOR ATRIAL FIBRILLATION

Local impedance (LI) measurement can predict tissue heating during RF ablation. To evaluate the utility of prespecified target LI to prospectively guide high power, short-duration (HPSD) ablation for PV isolation. This is a single-center prospective study 44 consecutive patients who underwent initial isolation AF. Circumferential around antrum each was performed using 4 mm tip open irrigation catheter with an sensor. energy applied at site power output 50 W. Adequacy application solely guided by measured from catheter. electrograms were not monitored Annotation applications based on predefined parameters: the: (1) stability <3 mm; (2) drops >5 Ω (regardless baseline LI) within first 5 seconds; and (3) duration seconds. Each tagged continued total 6-10 seconds LA posterior wall 10-15 other regions. If failed drop quickly (>5-Ω decrease delivery), interrupted adjusted achieve better contact, reapplied. stopped if esophageal temperature rose >40°C or dropped >30 Ω. Ultrahigh-density mapping after pass encircling all PVs inter-lesion distance mm. First-pass achieved in 163 175 (93.1%) 34/44 (77.3%). In (in patients), high-density identified 11 LA-PV conduction gaps sites where did meet annotation criteria (due instability, heating, lack sufficient drop). 7 Patients), 10 satisfy our protocol. Compared points gaps, without (suggestive acutely effective lesions) exhibited significantly larger absolute (16.4 ± 6.7 vs. 12.2 4.6 Ω, p=0.01) % change (14.8% 5.1% 10.9% 4%, p=0.013) delivery. The anatomical distribution shown Figure. No steam pops major complications occurred procedures. Our magnitude may be used safe successful HPSD