Predictors of left atrial appendage stunning after electrical cardioversion in patients with atrial fibrillation

The transient left atrial appendage (LAA) dysfunction after electrical cardioversion (CV), which is called as LAA-stunning, was found to be an important etiology of thrombus formation. The aim of the present study was to investigate the risk factors of LAA-stunning. This study included 134 patients who underwent catheter ablation for non-paroxysmal, non-valvular, and symptomatic atrial fibrillation (AF). Internal-CV was performed, and LAA emptying fraction (LAA-EF) was assessed using LAA-angiogram before and just after CV. LAA-stunning (defined as 10% reduction of LAA-EF after CV) was observed in 45/134 patients (34%). Patients in LAA-stunning group had longer duration of AF prior to CV, higher brain natriuretic peptide (BNP), higher prevalence of patients taking calcium blocker, larger left atrial (LA) diameter, elevated E wave, and larger LA volume than those in non LAA-stunning group. Multivariate analysis showed that longer duration of AF prior to CV (p = 0.015, OR 1.033 for 1 month extend, 95% CI 1.006-1.073) and elevated BNP (p = 0.038, OR 1.041 for each 10 pg/mL increase, 95% CI 1.001-1.009) were associated with LAA-stunning. In addition, all patients were divided into four groups based on the combination between duration of AF prior to CV and BNP; group 1 (low BNP/short-lasting AF), group 2 (high BNP/short-lasting AF), group 3 (low BNP/long-lasting AF), and group 4 (high BNP/long-lasting AF). The rate of LAA-stunning was the highest in the group 4 (55.6%). Elevated BNP and long duration of AF were associated with LAA stunning after electrical cardioversion.