Determinants of enhanced left atrial active emptying with aging: left atrial preload, contractility or both?
OBJECTIVE
Senile persons have reduced left ventricular (LV) relaxation and increased late diastolic filling. However, the determinant factor of the enhanced active emptying of the left atrium has not been well established.


METHODS
Subjects were 62 healthy individuals with a mean age of 58+/-19 (21-85) years. The biplane modified Simpson's rule was applied to measure left atrial (LA) volume at pre-atrial contraction (LAVpre) as an index of LA preload and LA volume change during atrial contraction (LASV) as an index of active LA emptying. These values were divided by the body surface area and represented as LAVpreI and LASVI, respectively. Postero-basal (dorsal cranial) left atrial wall velocity (LAWV) during atrial contraction as an index of LA contractility was measured in the apical three-chamber view by two-dimensional tissue Doppler echocardiography.


RESULTS
Age significantly correlated with mitral flow velocity (TMA), velocity-time integral during atrial contraction (TMAVTI) and LASVI (r= 0.63, p<0.001 and r=0.71, p<0.001, r=0.21, p=0.049, respectively). LAVpreI was significantly correlated with age (r=0.44, p<0.001), LASVI (r=0.71, p<0.001), TMA (r=0.31, p=0.008) and TMAVTI (r=0.40, p<0.001). LAWV remained unchanged with aging and had no correlation with TMA, TMAVTI or LASVI.


CONCLUSIONS
The enlargement of the LA in senile persons may be a major determinant of enhanced active LA emptying and the increased LA contractility may be less contributory.
Yoshida
Naoyasu
N
Department of Laboratory Medicine, Hiroshima Prefectural Hospital. n_yoshida0210@ybb.ne.jp
Okamoto
Mitsunori
M
Makita
Yuko
Y
Nanba
Kiyomi
K
Yoshizumi
Masao
M
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D000544:Alzheimer Disease / Q000503:physiopathology; D016279:Atrial Function, Left / Q000502:physiology*; D004452:Echocardiography; D015150:Echocardiography, Doppler; D005260:Female; D006325:Heart Atria / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000000981:diagnostic imaging / Q000502:physiology; D009200:Myocardial Contraction / Q000502:physiology*; D012039:Regional Blood Flow / Q000502:physiology