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

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.