Metabolic borderzone in acutely ischemic canine myocardium demonstrated by positron-CT (PCT)
Acute coronary ligation in dogs results in an area of myocardial dysfunction that exceeds the area of subsequent necrosis suggesting the existence of an ischemic ''borderzone'' of reversibly injured myocardium. The authors tested this hypothesis in 9 closed chest dogs with C-11 plamitate (CPA) and serial PCT imaging after an LAD occlusion. Using a blood flow (MBF) image obtained with iv N-13 ammonia prior to CPA, regions of interest were assigned on the serial CPA cross-sectional images to the center (IC) and border (IB) of the ischemic segment and to control myocardium (CO). CPA uptake was closely related to MBF (r=0.88) implicating flow as a major determinant of CPA uptake. Clearance helftimes (T 1/2) and relative sizes (RS) of the early rapid phase on the C-11 tissue time activity curves were determined for IC, IB and CO. In IC, MBF, RS and T 1/2 were markedly depressed indicating impaired CPA utilization and oxidation. In IB, MBF was less than in CO though only insignificantly, while RS and T 1/2 were highly abnormal. The authors conclude that FFA metabolism in areas adjacent to ischemic segments but without significant MBF decreases in abnormal, presenting evidence for a metabolic borderzone which now can be identified noninvasively with positron emission tomography.
- Research Organization:
- UCLA School of Medicine, Los Angeles, CA
- OSTI ID:
- 6520531
- Report Number(s):
- CONF-840619-
- Journal Information:
- J. Nucl. Med.; (United States), Journal Name: J. Nucl. Med.; (United States) Vol. 25:5; ISSN JNMEA
- Country of Publication:
- United States
- Language:
- English
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551001* -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
62 RADIOLOGY AND NUCLEAR MEDICINE
ANIMALS
BLOOD FLOW
BODY
CARDIOVASCULAR DISEASES
CARDIOVASCULAR SYSTEM
COMPUTERIZED TOMOGRAPHY
DIAGNOSTIC TECHNIQUES
DISEASES
DISTRIBUTION
DOGS
DRUGS
DYNAMIC FUNCTION STUDIES
EMISSION COMPUTED TOMOGRAPHY
HEART
ISCHEMIA
LABELLED COMPOUNDS
MAMMALS
METABOLISM
MUSCLES
MYOCARDIUM
ORGANS
POSITRON COMPUTED TOMOGRAPHY
RADIOPHARMACEUTICALS
TISSUE DISTRIBUTION
TOMOGRAPHY
UPTAKE
VASCULAR DISEASES
VERTEBRATES