Tamas Szili-Torok, MD, PhD; Steven Castellano, PhD; Melissa H. Kong, MD; Petr Neuzil, MD, PhD; Mark Hoogendijk, MD, PhD; Sip Wijchers, MD; Stefan G. Spitzer, MD; Andreas Rillig, MD; Vivek Y. Reddy, MD
ABSTRACT
Background
Electrographic flow (EGF) mapping visualizes near real-time cardiac wavefront propagation providing an assessment of substrate based on electrographic flow consistency (EGFC) and identifying active extra-pulmonary vein (PV) sources. AF was induced in persistent AF (PeAF) patients who presented for EGF-guided source ablation and were not in AF. Induced AF may have different characteristics than spontaneously persistent AF.
Objective
Compare source activity (SAC), EGFC, recurrence rates among patients mapped in spontaneous v. induced AF.
Methods
In FLOW-AF and AF-FLOW Registry, patients who did not present in AF underwent induction. Post-PV isolation (PVI) EGF maps were created from 1-min recordings using a 64-pole basket catheter in multiple standardized biatrial positions. Mean SAC calculated per position and overall SAC per patient was mean of all positions. Sources with SAC ≥26.5% were ablated.
Results
Of 69 patients analyzed with mean age 64±10yrs, 29% female, mean LA size 4.5±0.6cm, 86% (59/69) presented in spontaneous AF with mean overall SAC 22.7±5.7% v. 14% (10/69) were induced with mean overall SAC 27.6±6.9% (p=0.017). 100% (10/10) of induced AF patients were free from AF (FFAF) at 12 months post-PVI v. only 58% (34/59) of spontaneous AF patients (p=0.010). Mean EGFC did not differ between spontaneously persistent v. induced AF (p=0.22). Three recording pairs in a patient who presented in spontaneous AF, cardioverted, and was then re-induced revealed mean SAC increased in the paired recordings (3.7%±3.9% to 55.3%±9.0%, p=0.004), revealing sources that were not seen prior to induction. EGFC did not change between spontaneous and induced AF.
Conclusions
AF induced post-PVI revealed more clinically relevant extra-PV sources without change in EGFC and induced patients had lower AF recurrence. Induction may unmask sources that are less prevalent during spontaneously persistent AF; however, substrate assessment with EGFC remained unchanged whether AF was induced v. spontaneous.
Figure
EGFC measuring substrate remains unchanged while a clinically relevant source is unmasked in a patient who presented in spontaneous AF and subsequently cardioverted and was later reinduced.
