Abstract 2158 Compression of Posterior Left Atrium in Patients with Atrial Fibrillation -Association with Occurrence of Atrial Fibrillation
The incidence of compression of left atrium (LA) by the adjacent structures in patients with atrial fibrillation (AF) is not fully clarified. We assessed the incidence of LA compression(LAC) and examined relationship between LA compression and AF occurence.
Methods and Results: We performed 64-sliced enhanced multidetector computed tomography in consecutive 105 patients with paroxysmal AF underwent pulmonary vein isolation(PAF) and age, gender and clinical characteristics-matched 136 patients without history of AF(Control) and 109 patients with chronic AF(CAF).We classified LAC into 3 types: Type I; compression of left inferior pulmonary vein (PV) by the descending Aorta; Type II; compression of posterior LA or/and ostium of right inferior PV by the vertebral spine; Type III; combined with type I and type II. Type I compression was observed significantly higher in PAF and CAF than Control (15% vs 16% vs 1%, P<0.01). Type II compression was observed higher in CAF than PAF and Control(28% vs 9% vs 10% , P<0.01). Type III compression was observed only in CAF. LAC was observed totally 15(11%) patients in Control, 25(24%) patients in PAF, 60(55%) patients in CAF(P<0.01). It is reasonable that the incidence of LAC in CAF was increased according to LA dilatation(LA diameter; CAF:49±5mm vs Control;36±1mm vs PAF;37±2mm,P<0.01). However, in PAF, the incidence of LAC was higher significantly than Control without LA dilatation(LA diameter; 37±2mm vs 36±1mm,P=0.39). The present study disclosed higher incidence of LAC in PAF and CAF than Control. This result may implicate that LAC especially in patients with PAF may play a certain role in AF occurrence.