The School of Basic Medicine of Air Force Medical University, Xi' an, 710032, China.
Department of Cardiovascular Surgery, Rizhao Hospital Affiliated to Qingdao University, RizhaoInternational Heart Hospital, Qingdao, 276800, China.
Sci Rep. 2021 Nov 23;11(1):22800. doi: 10.1038/s41598-021-02196-0.
This study employed traditional and advanced echocardiographic techniques to assess comprehensively age- and sex-related changes in cardiovascular structure and function in wildtype (WT) mice. Forty-five normal adult wildtype mice were apportioned to groups based on age and sex: 2-month (young) male or female, and 24-month (old) male or female (n = 13, 13, 13, and 6, respectively). Each underwent 2-dimensional (2D) imaging echocardiography, Doppler, tissue Doppler imaging echocardiography, and speckle-tracking echocardiography (STE) for comparison of cardiovascular structure and function parameters. Compared to the young mice, the old had significantly higher body weight (BW), and lower diastolic and mean arterial pressure. The left ventricular (LV) end-diastolic and end-systolic volumes, and left ventricular mass, were significantly higher in the old mice. Within each sex, the cardiac diastolic and systolic function parameters were comparable between the young and old. Isovolumetric relaxation time (IVRT)/diastolic time interval (DT) and the maximum drop rate of pressure in LV (- dP/dtmax) were significantly lower in the old mice, while the LV relaxation time constant (Tau) was significantly higher. Spearman's rank correlation showed a positive association between IVRT/DT and - dp/dtmax (male r = 0.663; female r = 0.639). Among the males, the maximum rise rate of pressure in LV (+ dp/dtmax), and systolic global longitudinal strains and rates (S-GLS, S-GLSR) were significantly different between the young and old. Spearman's rank correlation showed positive association between S-GLS, S-GLSR and + dp/dtmax (r = 0.709 and r = 0.499). Regarding vascular structure, the ascending aorta systolic and diastolic diameters were significantly higher in the old mice compared with the young. The male mice had progressive, age-related aortic stiffness. Ageing in mice leads to changes in cardiovascular structure and cardiac diastolic function, but systolic function is relatively well preserved in females. Changes in cardiac function and arterial stiffness were more significant in males than females. Traditional ECG is better than STE for evaluating LV diastolic function; STE is better for LV systolic function.
这项研究采用传统和先进的超声心动图技术，全面评估了野生型（WT）小鼠心血管结构和功能的年龄和性别相关变化。将 45 只正常成年野生型小鼠按年龄和性别分为 2 组：2 个月（年轻）雄性或雌性，和 24 个月（年老）雄性或雌性（每组 n=13，13，13，6）。每组均接受二维（2D）成像超声心动图、多普勒、组织多普勒成像超声心动图和斑点追踪超声心动图（STE）检查，以比较心血管结构和功能参数。与年轻小鼠相比，老年小鼠体重（BW）显著增加，舒张压和平均动脉压降低。老年小鼠的左心室（LV）舒张末期和收缩末期容积以及左心室质量显著增加。在每个性别中，年轻和老年小鼠的心脏舒张和收缩功能参数相似。等容舒张时间（IVRT）/舒张时间间隔（DT）和 LV 最大压力下降率（-dp/dtmax）在老年小鼠中显著降低，而 LV 松弛时间常数（Tau）显著升高。Spearman 等级相关分析显示，IVRT/DT 与-dp/dtmax 呈正相关（雄性 r=0.663；雌性 r=0.639）。在雄性中，LV 最大压力上升率（+dp/dtmax）、收缩期整体纵向应变和速度（S-GLS、S-GLSR）在年轻和老年小鼠之间存在显著差异。Spearman 等级相关分析显示，S-GLS、S-GLSR 与+dp/dtmax 呈正相关（r=0.709 和 r=0.499）。在血管结构方面，老年小鼠的升主动脉收缩和舒张直径显著高于年轻小鼠。雄性小鼠的主动脉僵硬度随年龄呈进行性增加。在小鼠中，衰老导致心血管结构和心脏舒张功能发生变化，但女性的收缩功能相对较好。与女性相比，男性心脏功能和动脉僵硬度的变化更为显著。传统心电图（ECG）优于 STE 用于评估 LV 舒张功能；STE 更适合评估 LV 收缩功能。
