Effect of left atrial functions upon the functional capacity in patients with systolic heart failure

Abstract

Objective To assess left atrial (LA) function and its effect upon the functional capacity in patients with systolic heart failure (HF) using the two-dimensional (2D) speckle tracking echocardiography (STE). Patients and methods This study included 44 patients with systolic HF, ejection fraction less than 40%, sinus rhythm, and New York Heart Association (NYHA) class II–IV. All patients underwent six-minute walk test and conventional, tissue Doppler imaging (TDI), and 2D-STE echo. LA measures included LA dimensions and volumes for calculation of reservoir, conduit, and contractile functions. Peak atrial longitudinal strain (PALS) and peak atrial contractile strain were measured by 2D-STE. Based on NYHA class, patients were divided into group 1 (patients with NYHA II) and group 2 (patients with NYHA III–IV). Results There were no significant differences between both groups regarding demographic data. The 2D ejection fraction was significantly lower in group 2 compared with group I (P<0.05). Group 2 had significantly lower average LA peak systolic velocity (S′) and average LA late diastolic velocity (a′) by TDI compared with group 1, and also group 2 had significantly lower average PALS (16.3±7.2 vs. 11.3±4.4) and average peak atrial contractile strain (10.7±5.4 vs. 5.8±3.3, respectively; P<0.001), compared with group I. There were negative correlations between NYHA class and PALS (r=−0.436, P=0.003), whereas a positive correlation for PALS with six-minute walk distance (r=0.632, P=0.000). PALS was the most significant parameter that can predict limited exercise capacity. Conclusion LA mechanical functions were decreased in patients with systolic HF either measured by STE or TDI. PALS measured by 2D-STE is the most significant parameter correlated with functional capacity.

Keywords

• exercise capacity
• heart failure
• la function
• six-minute walk test
• speckle tracking echocardiography