Relationship of functional recovery to scar contraction after myocardial infarction in the canine left ventricle
We have previously reported that regional wall motion abnormalities in a canine model of acute myocardial infarction may show substantial improvement in the first 6 weeks after infarction. To determine whether the mechanism of this improvement in function is the result of scar contraction within the infarct, we studied the relationship between changes in regional wall motion defined by cross-sectional echocardiography and the regional concentration of radioactive microspheres injected immediately before coronary occlusion and sampled 6 weeks after occlusion. Eight dogs underwent serial echocardiographic and microsphere blood flow measurements immediately before and 30 minutes, 48 hours, 1 week, 3 weeks, and 6 weeks after ligation of the left anterior descending or the left circumflex coronary artery. Wall motion and blood flow were measured in the short-axis section of the left ventricle at the level of the midpapillary muscle in each 10-degree radial segment around the circumference of the ventricle. Infarct histology was assessed at 6 weeks by means of the same radial coordinate system. Control data were collected in a similar manner from four dogs that underwent sham operations and had no histologic evidence of infarction. In all of the animals with infarcts, but not in the sham animals, the calculated preocclusion endocardial and epicardial blood flow values in the histologic infarct zone (252 +/- 44 and 168 +/- 17 ml/min/100 gm, respectively, mean +/- SEM) were significantly higher than those in the normal opposite wall (endocardial: 106 +/- 3 ml/min/100 gm, p less than 0.01); epicardial: 108 +/- 3 ml/min/100 gm, p less than 0.01. The location and circumferential extent of myocardium showing this elevation of preocclusion blood flow correlated well (r = 0.93, p less than 0.001) with the location and circumferential extent of the histologic infarct.
- Research Organization:
- Massachusetts General Hospital, Boston (USA)
- OSTI ID:
- 6150110
- Journal Information:
- Am. Heart J.; (United States), Vol. 117:4
- Country of Publication:
- United States
- Language:
- English
Similar Records
Selective arterialization of the coronary venous system. Encouraging long-term flow evaluation utilizing radioactive microspheres
Effect of ischemia and postischemic dysfunction on myocardial uptake of technetium-99m-labeled methoxyisobutyl isonitrile and thallium-201
Related Subjects
HEART
BLOOD FLOW
BIOLOGICAL MODELS
BIOLOGICAL RECOVERY
CONTRACTION
DOGS
MICROSPHERES
MYOCARDIAL INFARCTION
PATHOLOGICAL CHANGES
RADIOISOTOPES
ULTRASONOGRAPHY
ANIMALS
BODY
CARDIOVASCULAR DISEASES
CARDIOVASCULAR SYSTEM
DISEASES
ISOTOPES
MAMMALS
ORGANS
RECOVERY
VERTEBRATES
550901* - Pathology- Tracer Techniques