SHA 103. Value of left atrial function in predicting effort capacity in patients with left ventricular systolic dysfunction

Abstract

Introduction: Left atrial (LA) function shares in left ventricular diastolic filling and, therefore, cardiac output during rest and exercise. However, there is scanty data about the relation between LA function and exercise performance in left ventricular systolic dysfunction patients (LVSD). Methods and results: This was a prospective, cross sectional study conducted on 25 patients with LVSD (EF < 40%) in sinus rhythm. LA volumes were measured using monoplane Simpson’s method. The measured LA volumes were the largest LA volume (Vmax), the smallest LA volume (Vmin), and the LA volume measured at the peak of P wave (Vp) of simultaneous ECG. Then, LA total emptying (Vmax Vmin), passive emptying (Vmax Vp) and active emptying (Vp Vmin) volumes were calculated. Then LA total emptying fraction (Vmax Vmin/Vmax), passive emptying fraction (Vmax Vp/Vmax), active emptying fraction (Vp Vmin/ Vp) were calculated. Patients were exercised using modified Bruce protocol, to determine their exercise capacity. The selected patient subdivided into two groups: group 1 with functional capacity <7 metabolic equivalent (METS) [17 patients] and group 2 with functional capacity P7 METS [8 patients]. There was a significant difference between the two groups regarding LA total emptying fraction (P 0.0006), LA active emptying fraction (P 0.045) and LA passive emptying fraction (P 0.004). Conclusion: Left atrial emptying fraction which can be easily obtained by routine echocardiography, is useful as a predictor of exercise capacity in LVSD patients.