Effects of cardiac contraction and coronary sinus pressure
elevation on collateral circulation.
Sato, Masahiko, Tomiyoshi Saito, Minoru Mitsugi, Shu-Ichi Saitoh,
Takeo Niitsuma, Kazuhira Maehara, Yukio Maruyama.
First Department of Internal Medicine, Fukushima Medical
College
APStracts 3:0189H, 1996.
Controlled coronary sinus occlusion was shown to retard necrosis of
ischemic myocardium. To elucidate this mechanism, regional myocardial
blood flow measurement using colored microspheres, which were
injected into left and right cororary artery after stopping the
coronary perfusion of left anterior descending coronary artery (LAD)
in 7 isolated canine hearts with induced atrioventricular block,
either paced at 120/min by direct right ventricular stimulation (B)
or during asystole induced by stopping pacing (NB), was performed
with and without coronary sinus pressure elevation to 30 mmHg (CS30).
Reginal myocardial blood flow in the LAD perfused area in NB without
CS30 (NB-CScont; 0.27 0.13 ml/min/g; mean SE) was significantly
greater than those in B without CS30 (B-CScont; 0.19 0.09 ml/min/g)
(P<0.05) and in NB with CS30 (NB-CS30; 0.19 0.09 ml/min/g) (P<0.05).
Regional myocardial blood flow of the LAD area in B with CS30 (B
-CS30; 0.23 0.10 ml/min/g) was significantly greater in comparison
with that at B-CScont and NB-CS30 (P<0.05). The augmentative
effect of its regional myocardial blood flow was observed only in the
periphery of the ischemic region but not in its center. Cardiac
contraction and CS30 impede regional myocardial blood flow in the
ischemic bed independently. The coexistence of these two factors
enhances regional myocardial blood flow. In conclusion, coronary
sinus pressure elevation in B may participate with augmenting
collateral flow.
Received 8 December 1995; accepted in final form 14 April 1996.
APS Manuscript Number H1145-5.
Article publication pending Am. J. Physiol. (Heart Circ. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 8 May 96