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Transmural unipolar electrogram change occurs within 7 s at the left atrial posterior wall during pulmonary vein isolation
Author(s) -
Tomlinson David R.,
Myles Madison,
Stevens Kara N.,
Streeter Adam J.
Publication year - 2019
Publication title -
pacing and clinical electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.686
H-Index - 101
eISSN - 1540-8159
pISSN - 0147-8389
DOI - 10.1111/pace.13729
Subject(s) - medicine , pulmonary vein , ablation , cardiology , rf ablation , catheter ablation , morphology (biology) , nuclear medicine , biology , genetics
Background To assess occurrence of a histologically validated measure of transmural (TM) atrial ablation—pure R unipolar electrogram (UE) morphology change—at first‐ablated left atrial posterior wall (LAPW) sites during contact force (CF)‐guided pulmonary vein isolation (PVI). Methods Objectively annotated VISITAG™ Module and CARTOREPLAY™ (Biosense Webster Inc., Diamond Bar, CA, USA) UE morphology data were retrospectively analyzed in 23 consecutive patients undergoing PVI under general anesthesia. Results PVI without spontaneous/dormant recovery was achieved in all, employing 16.3 (3.2) min of radiofrequency (RF; 30 W) energy. All first‐ablated LAPW sites demonstrated RS UE morphology preablation, with RF‐induced pure R UE morphology change in 98%. Time to pure R UE morphology was significantly shorter at left‐sided LAPW sites (4.9 [2.1] vs 6.7 [2.5] s; P = .02), with significantly greater impedance drop (median 13.5 vs 9.9 Ω; P = .003). Importantly, neither first‐site RF duration (14.9 vs 15.0 s) nor maximum ablation catheter tip distance moved (during RF) was significantly different, yet the mean CF was significantly higher at right‐sided sites (16.5 vs 11.2 g; P = .002). Concurrent impedance and objectively annotated bipolar electrogram (BE) data demonstrated ∼6‐8 Ω impedance drop and ∼30% BE decrease at the time of first pure R UE morphology change. Conclusions Using objective ablation site annotation, UE morphology evidence of TM RF effect was demonstrated far sooner than considered biologically possible according to the “conventional” 20‐40 s RF per‐site approach, with significantly greater ablative effect evident at left‐sided sites. This novel methodology represents a scientifically more rigorous foundation toward future research into the biological effects of RF ablation in vivo.