1Department of Cardiology Tenshi Hospital, 2Second Department of Internal Medicine School of Medicine Sapporo Medical University
Aging, Left atrial function
To assess the effects of aging on the left atrial contractile function, 170 normal subjects (84 males and 86 females; 40.0±16.9 years old) were analyzed echocardiographically. From an M-mode recording at the aortic root level, it was possible to examine the left atrial dimension index just prior to atrial contraction (DDal) as end-diastole, that after atrial contraction (DSal) as end-systole, maximum left atrial dimension index (DmaxI) and the interval between both timing (ETa). This made it possible to compute atrial filling fraction (AFF), the fractional shortening of the left atrium (FSa), and the mean velocity of circumferential fiber shortening of the left atrium (mVCFa). DDal, DSal, DmaxI and AFF increased with age, although aging did not alter the values of FSa and mVCFa. These findings suggest that left atrial contractility did not alter with age although the magnitude of preload recruitment to the left atrium increased with age for maintaining left ventricular filling.