| Co-Investigator(Kenkyū-buntansha) |
MIYAMOTO Shingo KYUSHU UNIVERSITY, MEDICAL INSTITUTE OF BIOREGULATION, LECTURER, 生体防御医学研究所, 助手 (40209945)
NOZAKI Masahiro KYUSHU UNIVERSITY, DEPT. OF GYNECOLOGY AND OBSTETRICS, SENIOR LECTURER, 医学部, 助手 (60228319)
KOYANAGI Takashi KYUSHU UNIVERSITY, DEPT. OF GYNECOLOGY AND OBSTETRICS, ASSOCIATE PROFESSOR, 医学部, 助教授 (30136452)
NAKANO Hitoo KYUSHU UNIVERSITY, DEPT. OF GYNECOLOGY AND OBSTETRICS, ASSOCIATE PROFESSOR, 医学部, 教授 (40038766)
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| Research Abstract |
We evaluated the developmental characteristics of both the cardiac performance and peripheral hemodynamics in the human fetus, with the view of assessing the relationship between the central and peripheral circulation.
In normal fetuses, flow velocities through the tricuspid and the mitral valves, in the ascending aorta, the pulmonary artery and the descending aorta gradually increased with advance in gestation. Fetal cardiac contractility, expressed by the fractional shortening using M-mode echocardiography, was constant between the second and the third trimester. These results showed that the increase in both intracardiac and peripheral circulating volume is dependent on the increase in the stroke volume based on the cardiac ventricular size. On the other hand, the placental and cerebral vascular resistance were found to decrease and increase, respectively, in advancing gestation.
Based on these values concerning fetal circulation obtained from normal cases, we evaluated hemodynamic ab
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errations in fetuses with various kinds of fetopathy. In cases with complete atrioventricular (AV) block without hydrops fetalis, the cardiac contractility showed the increase, probably due to compensate for the bradycardia. In cases with the paroxysmal supraventricular tachycardia, the cardiac contractility and the ventricular dimension showed the decrease and the increase, respectively, indicating tachycardia-induced cardiomyopathy. In addition, the fetus with the hepatic hemangioma, the recipient in twin-to-twin transfusion and the hydrops fetalis with AV block, the deviation of both the ventricular chamber sizes and the cardiac contractility showed the direction to compensate for fetal circulatory deviation. In the peripheral circulation, the cases with the intrauterine growth retardation, the fetal distress and the hydrops fetalis with abnormal heart rate patterns all showed the decrease in RI values in the middle cerebral artery, indicating the decrease in cerebral vascular resistance.
These results indicated that, in the human fetus, both the central, expressed by the cardiac performance, and the peripheral circulation have the interrelationship in addition to the independent circulatory regulations in each level, and that the evaluation of hemodynamic parameters might be useful for the understanding of the pathophysiology and the judgment of the effect in the fetal therapy in fetopathy. Less
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