[Evaluation of left ventricular diastolic function in canine acute myocardial ischemia using velocity vector imaging
Chuan Zhang1, Dao-Gang Zha, Rong-Sheng DU
1Department of Cardiology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China. zhanglang19991999@yahoo.com.cn
Objective:
To assess the value of velocity vector imaging (VVI) and quantitative tissue velocity imaging (QTVI) in assessing left ventricular diastolic function of the dogs with acute myocardial ischemia.
Methods:
Six healthy mongrel dogs were subjected to ligation of the left circumflex artery or left anterior descending artery to induce coronary artery stenosis of varying degrees. The mean peak diastolic velocity (Em) of the ventricular walls around the mitral annulus was recorded with VVI or QTVI in the coronary blood flow. The left ventricular end diastolic pressure (LVEDP) was measured with pigtail catheter in the left ventricle.
Results:
As the coronary blood flow decreased, LVEDP was gradually increased, and Em measured by VVI or QTVI were also gradually decreased. A good linear correlation was shown between Em measured by VVI or QTVI and LVEDP (r=-0.834, P<0.001, and r=-0.68, P<0.001, respectively). A significant difference was observed in the correlation coefficient between VVI and QTVI (Z=2.625, P=0.0087).
Conclusion:
VVI and QTVI both provide good noninvasive means for measuring left ventricular diastolic function. VVI, a new echocardiographic modality without angular dependence, is better than QTVI in evaluating left ventricular diastolic function.
