B-PO05-152 BASELINE CONDUCTION INTERVALS AND TRANS-ISTHMUS TIMING AND CORRELATION WITH ATRIAL FIBRILLATION

Abstract

Prevalence of atrial fibrillation (AF) in patients with typical atrial flutter (tAFL) is. higher than in patients without tAFL. Correlation between right atrial conduction velocity measured during tAFL ablation and prevalence of AF has not been described. We evaluated whether baseline conduction intervals or atrial conduction velocity as measured by trans-isthmus timing during tAFL ablation is correlated with prevalence and incidence of AF. We performed a retrospective analysis of 43 patients that underwent tAFL ablation. We measured baseline conduction intervals and trans-isthmus timing after CTI block and analyzed whether this was correlated with prevalence of AF. Trans-isthmus time was measured as the conduction time from proximal CS pacing to the lateral border of the CTI ablation line. T-tests and fisher exact tests were run on all the variables. A total of 43 patients who had a CTI ablation were studied. The mean age was 64 years. 22 of the patients had AF at the time of the procedure. Of the baseline conduction intervals, shorter QT and RR times were significant for less prevalence of AF with a p-value of <0.05. Also, a shorter trans-isthmus timing correlated with a significantly lower prevalence of AF (p = 0.036). In patients undergoing tAFL ablation, a longer QT, RR, and trans-isthmus times may correlate with a higher prevalence of AF. This may help guide aggressiveness of AF monitoring in patients presenting for tAFL ablation. Further investigation is needed.