Abstract 12295: The Timing of Appearance of Untimely Dissociated Potentials After Pulmonary Vein Isolation for Atrial Fibrillation is Related to the Respiratory Phase

Abstract

Introduction: Ectopic beats originating from the pulmonary vein (PV) trigger atrial fibrillation (AF). However, the mechanism and timing of Ectopic beat occurrence remain unclear. Hypothesis: The dissociated potentials (DPs) after pulmonary vein isolation (PVI) for AF are related to the respiratory phase and left atrial pressure (LAP). Methods: 93 patients underwent AF ablation under deep sedation and BiPAP ventilation. [Study1] Respiratory waveforms of 20 patients were recorded simultaneously with LAP. [Study2] In 73 patients, DPs after PVI or left atrial posterior wall (LAPW) isolation were recorded simultaneously with respiratory waveforms for 3 min, and the preceding coupling intervals (CI) of all DPs were measured. Sites with DPs frequencies <10/min were defined as rare DPs sites. In sites with DPs frequencies ≧10/min, sites where the number of DPs with CI shorter than the mean - SD of CI was greater than the number of DPs with CI longer than the mean + SD of CI were defined as short-coupling DPs sites, and long-coupling DPs sites were defined in the opposite cases. Results: [Study1] Respiratory waveforms showed fluctuations similar to LAP, and LAP increased within the respiratory interval in all patients (Fig.1). [Study2] The incidence of DPs on the left PV was lower than that on the right PV and LAPW (28 of 61 left PV 46%, 41 of 66 62%, 3 of 3 100%, P=0.0306). Additionally, the CI of DPs on the left PV was longer (3.1±5.4sec, 2.0±2.8, and 1.6±0.5, P<0.0001). The timing of appearance of DPs was not related to the respiratory phase in all DPs assessments (2126 beats during the respiratory interval and 2155 beats during the rest interval). However, inopportune DPs appeared during the specific respiratory phases: the respiratory interval for short-coupling DPs, and the rest interval for long-coupling DPs and rare DPs sites (P=0.016, Fig.2). Conclusions: The timing of appearance of untimely DPs is related to the respiratory phase and may be associated with an increase in LAP.