AJP - Heart and Circulatory Physiology, Vol 243, Issue 6 852-H855, Copyright © 1982 by American Physiological Society
Contrasting ischemic contraction patterns by zone and layer in canine myocardium
S. Hattori, W. S. Weintraub, J. B. Agarwal, M. M. Bodenheimer, V. S. Banka and R. H. Helfant
The effect of graded coronary occlusion on myocardial shortening in
different zones of the left ventricle is not clear. Therefore, in 15 dogs
ultrasonic crystals were used to evaluate the effect of graded coronary
occlusion on subendocardial and subepicardial contraction in both the left
anterior descending coronary artery (LAD) and left circumflex coronary
artery (Circ) distributions. Subepicardial shortening was evaluated along
both the long and short axes. In the LAD zones, segment shortening
decreased in parallel in the subendocardium and subepicardium. In the
circumflex zone subendocardial and subepicardial long axis shortening fell
off in parallel, while subepicardial short axis shortening fell off more
rapidly. Thus there is a close relationship between endocardial and
epicardial segment shortening following graded coronary occlusion. In the
circumflex zone, however, fiber orientation may affect the measurement of
segment motion.
