Left atrial dimensions determined by M-mode echocardiography in black and white older (> or =65 years) adults (The Cardiovascular Health Study).

Stroke and atrial fibrillation are common and serious illnesses in the elderly, the risks of which are substantially increased by left atrial (LA) enlargement. Despite growing recognition of the importance of LA enlargement, the distribution and correlates of LA dimension in the elderly have not been well defined. A total of 3,882 women and men aged >65 years were studied. Increased LA dimension was independently associated with increased weight, mitral annular calcium, regional wall motion abnormalities, mitral early peak inflow velocity, and left ventricular (LV) fractional shortening. Increased LA dimension was negatively associated with aortic leaflet thickening. The relation with LV fractional shortening was curvilinear with a nadir at 35% to 40%. LA dimension in black men was approximately 1.9 mm less than in white men in multivariate analyses. Adjustment for spirometric lung volumes and chest dimensions appeared to diminish the race-LA dimension relation. Thus, LA dimension is strongly associated with weight and with several echocardiographic valvular abnormalities; its relation with LV fractional shortening is U-shaped with a nadir at the borderline of LV functional impairment.