Hyperkinesis without the Frank-Starling mechanism in a nonischemic region of acutely ischemic excised canine heart

Circulation
Y GotoH Suga

Abstract

To determine the essential mechanism of increased systolic wall motion, i.e., hyperkinesis, in a nonischemic region (NIR) during acute ischemia, we simultaneously evaluated global and regional function of the excised, cross-circulated canine left ventricle connected to a volume servo pump before and after coronary occlusion. Regional areas were determined with pairs of orthogonal subendocardial sonomicrometers in the ischemic region (IR) and NIR. After coronary occlusion with left ventricular end-diastolic and stroke volumes kept constant, the amount of systolic area shrinkage (delta A) in NIR increased by 33 +/- 41% (p less than .05), despite a decrease in end-diastolic regional area by 3 +/- 4% (p less than .05). Regional work obtained from the wall tension-regional area (T-A) loop in NIR decreased by 50 +/- 24% due to a similar decrease in afterload despite the presence of hyperkinesis, indicating regional systolic unloading. When left ventricular end-diastolic volume was subsequently increased with a constant stroke volume, delta A in NIR increased at the expense of a further decrease in delta A in IR. The end-systolic T-A relationship in NIR remained unchanged, whereas that in IR markedly shifted rightward, suggesting that...Continue Reading

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Citations

Jan 17, 1991·European Journal of Pharmacology·R DomenechJ P Huidobro-Toro
May 1, 1993·Journal of the American College of Cardiology·Y GotoH Suga
Dec 1, 1994·Journal of the American College of Cardiology·T E MeyerP Foëx
Apr 30, 1998·Journal of the American College of Cardiology·K MiyajiS Takamoto
Jul 1, 1994·Acta Physiologica Scandinavica·S Birkeland, E Hexeberg
Jan 19, 2016·Frontiers in Physiology·João Sérgio NevesAdelino F Leite-Moreira
Mar 15, 2015·American Journal of Physiology. Heart and Circulatory Physiology·Ayana HiokiSatoshi Nakatani

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