运用三维彩色多普勒超声心动图计算每搏动能进行 心功能评价的实验研究

目的探讨三维彩色多普勒超声心动图在评价心脏每搏动能方面的应用价值.方法实验动物选用杂种犬10只,体重10.5～18.5kg.利用TomTec三维彩色多普勒成像工作站进行三维图像获取和重建,采用心导管测量左室压力.以三维彩色多普勒重建图像测量收缩期通过主动脉瓣口的血流速度和血流量;在此基础上计算出心脏每搏动能(Ek).分别在静息、静注多巴酚丁胺和结扎左冠状动脉前降支三种不同的心功能状态下进行实验.结果静息状态下心功能正常时,Ek为0.30g-m±0.09g-m;静注多巴酚丁胺后心功能增强,Ek测值为0.58g-m±0.13g-m,较静息心功能正常状态明显升高(P＜0.05);结扎左冠状动脉前降支后心功能减弱,Ek测值为0.15g-m±0.04g-m,较静息心功能正常状态明显降低(P＜0.05).结论利用三维彩色多普勒超声心动图的血流测值可以计算出心脏每搏动能(Ek),并能够可靠地反映心脏收缩功能的变化,为全面准确地评价心脏泵血功能提供了新的无创性手段.

An Experimental Study on Assessment of Cardiac Function with Stroke Kinetic Energy Using Three-dimensional Color Doppler Echocardiography

Objective To evaluate the value of three-dimension color Doppler echocardiography(3D-CDE) in evaluating stroke kinetic energy. Methods Ten mongrels weighing from 10.5~18.5kg were studied. The anaesthesized dogs were examined with color Doppler echocardiography. The three-dimensional images were acquired and reconstructed by the three-dimensional color Doppler reconstruction system (Echo-scan, TomTec). The velocity and volume of blood flow through aortic orifice during systole were measured using three-dimensional color Doppler imagings. The heart stroke kinetic energy (E_k) was calculated according to velocity and volume of blood flow. The systolic left ventricular pressure (LVSP) was measured with cardiac catheter. The experiments were accomplished on the conditions of static, adminstration of Dobutamine and occlusion of anterior descending branch of left coronary artery respectively. Results The E_k derived by 3D-CDE is 0.30g-m±0.09g-m when cardiac systolic function is normal on the static condition. After administration of Dobutamine, cardiac systolic function was enhanced, E_k was increased to 0.58g-m±0.13g-m and was significantly higher than static condition (P<0.05). After occlusion of anterior descending branch of left coronary artery, cardiac systolic function was weakened, E_k was decreased to 0.15g-m±0.04g-m and was significantly lower than static conditon (P<0.05). Conclusion The E_k calculated by measuring value of flow using three-dimensional color Doppler echocardiography is reliable for assessing cardiac systolic function, and it is a new noninvasive method for overall and accurate assessment of cardiac function.