Improvement of Atrial Function and Atrial Reverse Remodeling After Cardiac Resynchronization Therapy for Heart Failure

Objectives: We sought to examine whether cardiac resynchronization therapy (CRT) improves atrial function and induces atrial reverse remodeling. Background: Cardiac resynchronization therapy is an established therapy for advanced heart failure with prolonged QRS duration, which improves left ventricle (LV) function and is associated with LV reverse remodeling. Methods: A total of 107 heart failure patients (66 ± 11 years) who received CRT and were followed up for 3 months were studied. Atrial function was assessed by M-mode, 2-dimensional echocardiography, transmitral Doppler, tissue Doppler velocity, and strain (ε) imaging. Left atrial (LA) emptying fraction based on the change in areas (LAA-EF) and volumes (LAV-EF) were calculated. The LV reverse remodeling was defined by a reduction of LV end-systolic volume >10%. Results: In the responders of LV reverse remodeling (n = 62), LAA-EF and LAV-EF were significantly increased (p < 0.001). Responders also had significant decrease in LA size area and volumetric measurements, both before (p < 0.05) and after atrial systole (p < 0.001). However, these parameters were unchanged in the nonresponders (n = 45, p = NS). In the responders, tissue Doppler velocity analysis showed improvement of contraction velocity in both left (p = 0.005) and right atria (p = 0.018), whereas ε in both atria were increased in all the phases of cardiac cycle, namely ventricular end-systole (p < 0.001), early diastole (p < 0.001), and late diastole (p = 0.007). Conclusions: Cardiac resynchronization therapy improves both left and right atrial pump function. The increase in atrial ε throughout the cardiac cycle is likely reflecting the improvement of atrial compliance. These changes lead to LA reverse remodeling with reduction of LA size before and after atrial systole. [Copyright &y& Elsevier]