Abstract 21164: New Pulmonary Vein Derived Theory of Atrial Fibrillation

Abstract

Introduction: Pulmonary veins (PV) is a major source of triggers for AF. However, the mechanism underlying the rapid firing of PV muscle sleeve is not fully understood. Hypothesis: AF is related to the compensatory increase in PV load in patients with pneumonectomy. Methods: A cohort of 128 patients were recruited and assigned to three groups, group 1: patients with left-sided pneumonectomy (N = 47), group 2: patients with right sided pneumonectomy (N = 21), and control group: patients with paroxysmal AF (N = 60). All patients underwent echocardiography and CT scan preoperatively; PVI was performed in three groups; 24-hour Holter monitoring was performed during 1-year of follow-up. Results: All patients in group 1 and 2 had paroxysmal AF, occurring decades after pneumonectomy. No inter-group differences in left atrial diameter were seen. The average diameter of LSPV (17.2±1.4 mm) and LIPV (14.7±1.2 mm) in group 1 was larger than those in control group (13.6±1.0 mm and 9.9±0.9 mm, P<0.01). The diameter of RSPV and RIPV in group 2 (15.1±1.3 mm and 14.5±1.1 mm) and control group (13.2±1.3 mm and 10.2±1.2 mm) also showed significant differences (P<0.01). Electrical activity in group 1 and 2 could be recorded in all the PV stumps. After isolation of contralateral PV, AF was terminated in 91.5% and 85.7% of patients in group 1 and group 2. During follow-up, the incidence of AF episodes was not significantly different among three groups. Conclusions: the PV-derived mechanism of AF depends on a compensative increase in contralateral PV load in patients that have undergone pneumonectomy, and partial PV mediated AF is hard to progress into persistent state.