超声心动图结合心导管评价舒张功能减低犬心脏-血管耦联

Evaluation of ventricular-vascular coupling in canine with diastolic dysfunction by echocardiography combined with cardiac catheterization

目的应用超声心动图结合心导管观察起搏前、后犬的心脏功能变化情况,探讨超声评价舒张功能减低犬心脏-血管耦联的价值。方法应用超声心动图于实验犬右心室心尖起搏处获取起搏前、后二尖瓣舒张早、晚期血流速度峰值(E峰、A峰);二尖瓣环左室侧壁收缩期速度峰值(Sw峰),舒张早、晚期速度峰值(Ew峰、Aw峰),计算A/E、E/Ew;心导管检测左心室内压最大上升速率(+dp/dtmax)、最大下降速率(-dp/dtmax)、心室开始收缩至发生+dp/dtmax的间隔时间(t-dp/dtmax)、左心室收缩峰压(LVSP)、左心室收缩末压(LVESP)及左心室舒张压(LVDP);计算左心室收缩末期弹性(Ees)、有效动脉弹性(Ea)和心脏-血管耦联指数(Ea/Ees)。结果①起搏后实验犬A峰、Aw峰和E/Ew增高,与起搏前比较差异均有统计学意义(均P<0.05);E峰减低、Sw峰和Ew减低,A/E增高,但与起搏前比较差异均无统计学意义;②起搏后实验犬+dp/dtmax增大,-dp/dtmax减低,LVDP增高,与起搏前比较差异均有统计学意义(均P<0.05);起搏后,实验犬Ees减低,相关分析提示,Ees与+dp/dtmax呈负相关(P<0.05);Ea增高,Ea与t-dp/dtmax呈正相关(P<0.05);Ea/Ees增高,与起搏前比较差异有统计学意义(P<0.05)。结论超声心动图结合心导管可无创检测舒张功能减低犬的心脏-血管耦联关系。

Objective To observe cardiac function by echocardiography combined with cardiac catheterization before and after pacing and to explore the value of uhrasonography in the evaluation of ventricular-vascular coupling in canine with diastolic dysfunction. Methods Right ventricular apical pacing was established on the beagle dogs. Before and after pacing, the peak of early diastolic flow velocities （ E ） and the peak of atrial flow velocities （A）were measured. The sample volume was paced at lateral mitral annulus, and the systolic velocity （Sw）, the early diastolic myocardial velocity （Ew）, the late diastolic myocardial velocity （Aw） were also measured. The ratio of A/E and E/Ew were calculated. The peak pressure-rise rate （＋dp/dtmax）, the peak pressure-fall rate（-dp/dtmax）, the interval from LV systole to ＋dp/dtmax as t-dp/dt max（t-dp/dtmax）, the LV systolic peak pressure （LVSP）, the LV end-systolic pressure （LVESP）, and LV diastolic pressure （ LVDP）were measured by cardiac catheterization. LV end-systolic elastance （Ees）, effective arterial elastance（Ea） and ventricular-vascular index（ Ea/Ees ） were calculated according to the formulas. Results Compared with baseline, the A peak, Aw peak and E/Ew were increased （P〈0.05）. The E peak, Sw and Ew peak were decreased（P〉0.05 ）, but the A/E was increased after pacing（P〉0.05 ）. After pacing, the LVDP and the ＋dp/dtmax were raised, but the -dp/dtmax was decreased （P〈0.05）. After pacing, the Ees was decreased and negatively correlated with ＋dp/dtmax （P 〈0.05）. The Ea was increased and positively correlated with t-dp/dtmax （P〈0.05）.The Ea/Ees was increased after pacing and significantly different from that before pacing（P〈0.05 ）. Conclusion The elasticity of myocardium and cardiac function can be assessed noninvasively by echocardiography combined with cardiac catheterization.