Left Atrial Volume in Normal Japanese Adults

Background Two-dimensional (D) echocardiography-derived left atrial (LA) volume has been shown to provide a more accurate assessment of LA size than the M-mode LA dimension. Our objective was to provide reference ranges of LA volume in healthy Japanese adults. Methods and Results The study subjects consisted of 105 Japanese adults, with a mean age of 39±13 years (range 20-63 years old). All subjects had normal ejection fraction (>55%), no wall motion abnormalities, normal diastolic function, no valvular disease, and normal sinus rhythm. The maximum LA volume, at left ventricular end-systole just before the opening of the mitral valve, was measured by using the bi-apical (4- and 2-chamber views) Simpson's rule. Both the absolute LA volume and the volume corrected by body surface area (LA volume index) were obtained. The LA volume ranged from 21 to 53 ml (mean 37±8 ml) and the LA volume index ranged from 13 to 30 ml/m2 (mean 22±4 ml/m2). The mean LA volume index + 2SDs was 30 ml/m2. Conclusions Recognition of the upper limits of LA volume in normal Japanese subjects is of particular clinical relevance because it offers the opportunity of pathological LA remodeling diagnosis. (Circ J 2006; 70: 285 - 288)