PMID: 46718Apr 1, 1975

Myocardial conduction defects in association with compression of the umbilical cord. Experimental observations on fetal baboons

American Journal of Obstetrics and Gynecology
M N YehL S James

Abstract

Experiments have been performed in 16 pregnant baboons to study in greater detail the fetal hemodynamics, heart rate, and acid-base changes during occlusion of the umbilical cord. A total of 32 observations were made during which the umbilical cord was completely occluded with the fetus intact in utero; 11 were made after the intravenous administration of atropine, 0.01 to 0.02 mg. per kilogram, to fetus. Various degrees of conduction defects occurred in 17 of 21 observations before atropine. Complete atrioventricular block with extrasystoles was seen six times. Upon release of cord occlusion, there was a rapid recovery of myocardial conduction. Atropine prevented myocardial conduction defects; bradycardia was less and the onset was delayed. These observations suggest that myocardial conduction defects which occur during the course of cord occlusion are due to parasynpathetic stimulation. They could also be due to an increased sensitivity of the fetal myocardium to acetylcholine under hypoxic conditions. No recommendation can be made at the present time with regard to the administration of atropine to the fetus when cord compression is suspected on clinical grounds.

References

Mar 1, 1994·American Journal of Obstetrics and Gynecology·R T WakaiC B Martin
Jun 6, 2002·Ultrasound in Obstetrics & Gynecology : the Official Journal of the International Society of Ultrasound in Obstetrics and Gynecology·M KrappU Gembruch
Jan 1, 1995·Archives of Disease in Childhood. Fetal and Neonatal Edition·M P MohajerD K James
Jan 1, 1981·Journal of Perinatal Medicine·N V Strizhova, B M Petrikovsky
May 4, 2012·American Journal of Physiology. Regulatory, Integrative and Comparative Physiology·Lindsea C BoothLaura Bennet
Apr 1, 1994·International Journal of Developmental Neuroscience : the Official Journal of the International Society for Developmental Neuroscience·Z BiniendaS F Ali
Jul 17, 2015·Acta Obstetricia Et Gynecologica Scandinavica·Julie Sletten, Jørg Kessler
Sep 14, 2018·BMC Pregnancy and Childbirth·Vinayak SmithEuan Morrison Wallace
Sep 1, 1988·Asia-Oceania Journal of Obstetrics and Gynaecology·G OhelD Navot

Related Concepts

Fetal Structures
Dioxygen
Heart Block
Bradycardia
Diastolic Blood Pressure
Papio
Umbilical Cord Structure
Closure by Clamp
Atrioventricular Block
Blood

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