Cardiovascular effects of isoproterenol in the preterm newborn lamb
A study was made of the effects of an isoproterenol infusion on cardiac output and the distribution of blood flow in 5 preterm newborn lambs. Cardiac output and regional organ blood flow were measured by injecting radionuclide-labeled microspheres into the superior vena cava and left ventricle. We found that an average infusion of 0.5 microgram/kg X min of isoproterenol increased cardiac output 73% which correlated closely with an increase in stroke volume, but not with HR. The increase in systemic blood flow was distributed exclusively to the myocardium and skeletal muscle, bone, and skin. We conclude that isoproterenol increases cardiac output in preterm newborn lambs similarly to adults and that the stroke volume of the immature heart is more changeable than previously thought.
- Research Organization:
- Massachusetts General Hospital, Boston
- OSTI ID:
- 6746904
- Journal Information:
- Crit. Care Med.; (United States), Vol. 12:1
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
BODY AREAS
RADIOISOTOPE SCANNING
HEART
BLOOD FLOW
STIMULATION
SYMPATHOMIMETICS
BIOLOGICAL EFFECTS
INTRAVENOUS INJECTION
MEASURING METHODS
MICROSPHERES
NEONATES
SHEEP
TRACER TECHNIQUES
ANIMALS
AUTONOMIC NERVOUS SYSTEM AGENTS
BODY
CARDIOVASCULAR SYSTEM
COUNTING TECHNIQUES
DOMESTIC ANIMALS
DRUGS
INJECTION
INTAKE
ISOTOPE APPLICATIONS
MAMMALS
ORGANS
RUMINANTS
VERTEBRATES
550601* - Medicine- Unsealed Radionuclides in Diagnostics