新西兰兔腹主动脉缩窄术后心肌收缩和舒张功能的变化

Change of myocardial systolic and diastolic function in New Zealand rabbits after abdominal aortic constriction

目的观察新西兰兔腹主动脉缩窄术后不同时间点心肌收缩和舒张功能的变化。方法30只新西兰兔随机分为2组:手术组(20只)行腹主动脉缩窄术,假手术组(10只)作为对照。术后观察兔精神状态、饮食、活动等变化。手术前后监测血流动力学变化并定期行超声心动图检查。结果术后4周,手术组出现心室肥厚,等容舒张时间延长。术后8周,组织多普勒提示二尖瓣舒张早期血流峰速与舒张晚期血流峰速比值和心肌收缩期血流峰速降低,左心室舒张末压升高(P<0.05);而射血分数无显著差异。结论腹主动脉缩窄术后可造成舒张功能的损伤,同时也伴有轻度收缩功能的损伤。

Objective To examine the change of myocardial systolic and diastolic function in New Zealand rabbits at different time points after abdominal aortic constriction. Method Thirty male New Zealand rabbits were randomly assigned to two groups： operated group （ n =20） and shamoperated group （ n = 10）. In operated group, aortic constriction was performed; and in sham-operated group, only a suture was placed under abdominal aorta without constriction. The mental status, apetite and vital signs were followed up. Systolic and diastolic function and systemic hemodynamics were investigated by echocardiography and left ventricle catheter. Results In operated group, ventricular hypertrophy appeared and isovolumic relaxation time increased 4 weeks after operation. At 8th week, tissue doppler image indicated that e/a ratio,peak myocardial sustained systolic velocity decreased, left ventricular end-diastolic pressure increased. However, the ejection fraction did not change obviously. Conclusion Abdominal aortic constriction resulted in myocardial diastolic dysfunction associated with mild systolic dysfunction.