Regionalizing Non-Pulmonary Vein Triggers for Atrial Fibrillation Using Timing and Activation Pattern of Intracardiac Electrograms From Two Linear Decapolar Catheters

Introduction Targeting non-pulmonary vein triggers (NPVTs) after pulmonary vein isolation (PVI) reduces atrial fibrillation (AF) recurrence. However, NPVTs are often single atrial ectopic beats with surface P wave obscured, making regionalization a challenge. We aimed to construct an algorithm to regionalize the site of origin of NPVTs using exclusively intracardiac electrograms from two standardly positioned linear decapolar catheters positioned 1) in the postero-lateral right atrium, along crista terminalis (CT) with distal bipole pair extending into SVC, and 2) in the coronary sinus (CS), with proximal bipole pair at CS ostium. Methods In 42 patients with AF, after PVI, we paced at 15 sites where NPVTs commonly arise (Figure 1). For each pacing site we analyzed activation sequence of the CS catheter electrogram (simultaneous/chevron/inverse chevron/distal-proximal/proximal-distal) and the timing (CSCT time) between the earliest electrograms from the two decapolar catheters. Negative CSCT time indicates CT catheter electrogram is earliest, positive indicates CS catheter electrogram is earliest (Figure 2, lower right). Results In this patient cohort (71% male, 57% persistent AF, 52% left atrial dilation), our algorithm was able to group the 15 pacing sites, into 7 clinically useful and distinct regions with high precision (positive predictive value range 81-99%, Figure 2). Conclusions An algorithm defined by the activation sequence and timing of electrograms from two linear multipolar catheters allows for accurate regionalization of NPVTs. This may be used to expedite identification of a region of interest to guide further focused detailed mapping of AF NPVTs.