Research on age-related changes in cardiac structure and function using transthoracic high-frequency ultrasonography in Wistar rats / 中华老年医学杂志

ABSTRACT

Objective To determine the cardiac structure and function by transthoracic highfrequency ultrasonography in Wistar rats, and to explore the patterns of age-related changes.Methods Male Wistar rats aged 1, 2, 5, 12, and 20 months (n= 12 each group) underwent transthoracic echocardiographic analysis to examine the parameters of cardiac structure and function.Finally, the rats were sacrificed and the left ventricles were weighed. Results The left atrial dimension (LAD), left ventricular end-diastolic diameter (LVEDD), interventricular septum thickness at diastole (IVSD), left ventricular posterior wall thickness (LVPWd) and left ventricular mass (LVM) increased with age (all P ＜ 0.05 ) . There was a positive relationship between echocardiographic value and the autopsy weight LVM (r=0. 78, P＜0.01). There were no statistical significances in ejection fraction and fractional shortening among groups (all P＞0.05). Isovolumic relaxation time (IVRT) prolonged with age (P＜0. 01). After 2 month-old, tissue Doppler imaging Ea gradually decreased with age, Aa tended to increase with age. Ea/Aa ratio was more than 1 value in 1-, 2- and 5-months-old group, and it was less than 1 value in 12-, and 20-month-old group.Multivariate analysis showed that age was the influence factor of LAD, LVEDd and Ea. Conclusions Transthoracic high-frequency ultrasonography can be used to evaluate cardiac structure and function in rats; In aged rats, the wall-thickness, LAD and LVEDd are significantly increased. There is no significant change in systolic function, but diastolic function is decreased.