Evaluation of Flow Dynamics in the Left Ventricle Related to Wall Motion Abnormality Using Transpulmonary Contrast Echocardiography
外山 裕子, 水重 克文, 森田 久樹, 深田 英利, 平林 浩一, 野崎 士郎, 大森 浩二, 千田 彰一, 松尾 裕英
Yuko TOYAMA, Katsufumi MIZUSHIGE, Hisaki MORITA, Hidetoshi FUKADA, Koichi HIRABAYASHI, Shiro NOZAKI, Koji OHMORI, Shoichi SENDA, Hirohide MATSUO
The Second Department of Internal Medicine, Kagawa Medical School
Contrast echocardiography, Wall motion abnormality, Flow dynamics, Densitometric analysis, Blood stasis
We evaluated flow dynamics in the left ventricle related to wall motion abnormality using yideodensitometric analysis of transpulmonary contrast echocardiography. The subjects consisted of 8 normal persons, 22 patients with old myocardial infarction (OMI) and 6 patients with dilated cardiomyopathy (DCM). All 36 subjects underwent two-dimensional echocardiographic examination before, during and after intravenous injection of sonicated albumin as a contrast agent(CA). The washout dynamics of CA at the site of the mitral orifice(a) and mid-left ventricle(b) were assessedusing a dens itometric time-intensity curve. We calculated the heart rate from contrast appearance to half-contrast disappearance at each site, as Ta and Tb, respectively. We obtained contrast enhancement in 28 subjects. The contrast effect showed differences among individuals, and the time-intensity curve showed periodic changes corresponding to respiration. We classified patients with wall motion abnormality into two groups(A, B) according to characteristic findings from densitometry: Group A, Tb-Ta≤3(OMI 9, DCM 1); Group B, Tb-Ta≥4(OMI 8, DCM 2). Subjects for whom we could not obtain contrast enhancement comprised Group C(OMI 5, DCM 3). The 8 normal subjects formed Group N. We compared stroke volume(SV), ejection fraction(EF) and wall motion index(WMI) using Doppler echocardiography among all four groups. Group A had wall motion abnormality, but no dilation of the left ventricle, and SV and EF of Group A were not significantly lower than those of Group N. On the other hand, Group B had more severe wall motion abnormality and a dilated left ventricle, and SV and EF of Group B was significantly lower than in Groups N and A. Group C had the most severe wall motion abnormality and dilated left ventricle. SV and EF of Group C was the lowest among the four groups. The value of Tb-Ta correlated with these parameters of left ventricular function. As the left ventricular function became lower, Tb-Ta became longer. Therefore, we concluded that densitometric analysis of CA is a feasible technique for evaluation of the blood stasis in the left ventricle.