2003 Fiscal Year Final Research Report Summary
Importance of Nitric Oxide for Cerebral Circulation in Fetal Tachyarrhythmia
| Project/Area Number |
13670829
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Pediatrics
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| Research Institution | Jichi Medical School |
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Principal Investigator |
SHIRAISHI Hirohiko Jichi Medical School, Pediatrics, Professor, 医学部, 教授 (40187521)
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| Co-Investigator(Kenkyū-buntansha) |
KIKUCHI Yutaka Jichi Medical School, Pediatrics, Assistant Professor, 講師 (90260835)
HOSHINA Masaru Jichi Medical School, Pediatrics, Assistant Professor, 講師 (20291635)
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| Project Period (FY) |
2001 – 2003
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| Keywords | Supraventricular tachycardia / Ventricular tachycardia / fetus / Cerebral Circulation / Nitric Oxide |
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| Research Abstract |
To evaluate the hemodynamic effect of rapid left atrial pacing on fetal circulation, we made a fetal supraventricular tachyarrhythmia model and measured the aortic pressure, central venous pressure, and left and right ventricular output in fetal lambs. Under maternal anesthesia, the uterus was opened, and under local anesthesia, catheters were inserted into the fetal superior vena cava and ascending aorta through a neck incision. Pacing leads were then sutured onto the fetal left atrial appendage via left thoracotomy. Ventricular output was estimated using an echocardiography by a transuterine approach. Fetal hemodynamics were observed without pacing (control), and at the pacing rates of 200, 300, 350, and 400/min. The aortic pressure decreased when the left atrium was paced at 300/min or more and central venous pressure increased when the left atrium was paced at 350/min or more. The left and right ventricular output decreased when the left atrium was paced at 350/min or more. Fetal circulatory failure was initially confirmed when the left atrium was paced at 300/min in this left atrial tachyarrhythmia model.
During fetal tachycardia, administration of Nomega-nitro-L-arginine methyl ester (L-NAME) decreased fetal cerebral blood flow. NO is essential for fetal cerebral circulation in tachycardia.
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