Left atrial activation and asymmetric anatomical remodeling in patients with atrial fibrillation: The relation between anatomy and function

Abstract

Background: Identifying patients with advanced left atrial (LA) remodeling before catheter ablation (CA) of atrial fibrillation (AF) is crucial. Hypothesis: This study aimed to identify echocardiographic parameters associated with changes in anatomy and conduction properties of the left atrium (LA). Methods: We examined 75 AF patients prior to CA and measured the intervals from the P-wave-onset to four mitral annulus sites by pulsed-wave tissue Doppler imaging (PW-TDI). Patients were grouped to an upward U-pattern (delayed anterior activation) and a downward D-pattern (earliest LA activation anterior). CT-data were used to measure the LA volume (LAV). LAV was divided into anterior- (LA-A) and posterior-parts by a plane, parallel to the posterior wall and between the veins and the appendage, to calculate the asymmetry index (ASI = LA-A/LAV). Results: Patients with U-pattern (n = 66) had a higher ASI (65 ± 6 vs. 61 ± 3%, p =.014), older age (61 ± 11 vs. 51 ± 11 years, p =.03) and more diastolic dysfunction (71 vs. 22%, p =.008) Multivariate regression showed that age (OR 1.1 per year, CI 1.007–1.199) and diastolic dysfunction (OR 6.36, CI 1.132–35.7, p =.036) were independent predictors of the U-pattern. Diastolic dysfunction (B 4.49, CI 1.61–7.37, p =.003) was the only independent predictor of ASI in linear regression analysis. Conclusion: AF patients with a U-pattern have an increased LA asymmetry. Diastolic dysfunction is a common cause of this LA activation and remodeling. Therefore, detection of a U-pattern signifies patients with advanced AF and may facilitate selection for an appropriate ablation strategy.