scholarly journals Relation between changes in blood flow of the contralateral coronary artery and the angiographic extent and function of recruitable collateral vessels arising from this artery during balloon coronary occlusion

1994 ◽  
Vol 23 (4) ◽  
pp. 869-878 ◽  
Author(s):  
Michael K. Kyriakidis ◽  
Panaghiotis N. Petropoulakis ◽  
Costas A. Tentolouris ◽  
Stelios A. Marakas ◽  
Athanassios G. Antonopoulos ◽  
...  
Keyword(s):  
Blood Flow ◽  
Coronary Artery ◽  
Coronary Occlusion ◽  
Collateral Vessels ◽  
And Function

Myocardial blood flow and function during gradual coronary occlusion in awake dog

1983 ◽  
Vol 244 (1) ◽  
pp. H60-H67 ◽  
Author(s):  
R. C. Hill ◽  
L. H. Kleinman ◽  
W. H. Tiller ◽  
W. R. Chitwood ◽  
J. C. Rembert ◽  
...  
Keyword(s):  
Blood Flow ◽  
Coronary Artery ◽  
Coronary Occlusion ◽  
Treadmill Exercise ◽  
Regional Blood Flow ◽  
Mean Flow ◽  
Flow Probe ◽  
Circumflex Artery ◽  
Electromagnetic Flow Probe ◽  
And Function

The purpose of this study was to correlate dimensions and transmural blood flow in a segment of myocardium supplied by a coronary artery undergoing gradual closure. Nine adult dogs were instrumented with an electromagnetic flow probe, pneumatic occluder, and an ameroid constrictor on the circumflex coronary artery. Ultrasonic crystals were implanted 10 mm from the external surface of the left ventricle in a segment perfused by the circumflex artery. Regional blood flow was determined with 7- to 10-microns radiolabeled microspheres. Data were collected in the awake state at rest before closure began (control), during partial closure, and immediately after total closure. Seven of the nine animals were studied after occlusion during treadmill exercise. During both partial and total closure at rest the rate and extent of systolic shortening as well as the transmural blood flow were unchanged from control. During treadmill exercise mean flow increased. However, flow was redistributed away from the inner two layers causing deterioration in both the rate and extent of shortening of this segment. These data suggest that, although regional myocardial function and flow can be maintained at rest by the immature canine collateral circulation, these parameters are impaired markedly during augmented flow with exercise.

Effect of nitroglycerin on myocardial collateral conductance in awake dogs

1988 ◽  
Vol 254 (4) ◽  
pp. H751-H755
Author(s):  
S. Brazzamano ◽  
J. C. Rembert ◽  
J. C. Greenfield
Keyword(s):  
Blood Flow ◽  
Pressure Gradient ◽  
Collateral Circulation ◽  
Coronary Occlusion ◽  
Mean Value ◽  
Coronary Collateral Circulation ◽  
Control Value ◽  
Coronary Pressure ◽  
The Mean ◽  
Collateral Vessels

Conductance of the coronary collateral circulation during the course of two abrupt circumflex coronary occlusions (pre- and posttreatment with nitroglycerin) was measured in awake dogs approximately 2 wk after collateral vessels were stimulated to develop. The pressure gradient from the central aorta to the distal circumflex coronary artery was measured, and myocardial blood flow was determined by 9-microns radioactive microspheres at 30 s and 4 min after coronary occlusions. Collateral conductance was calculated as mean collateral blood flow divided by the mean aorta-coronary pressure gradient. Before nitroglycerin, collateral conductance increased in all eight dogs from 30 s to 4 min by a mean value of 0.006 +/- 0.003 ml.min-1.g-1.mmHg-1. After nitroglycerin administration, the conductance at 30 s increased from the prenitroglycerin control value of 0.009 +/- 0.008 to 0.014 +/- 0.012 ml.min-1.g-1.mmHg-1, P less than 0.03. The mean change in conductance from 30 s to 4 min postnitroglycerin 0.003 +/- 0.003 ml.min-1.g-1.mmHg-1 was significantly less than during prenitroglycerin (P = 0.01). These data indicate that an increase in conductance during coronary occlusion occurs even in the immature collateral circulation. This effect presumably takes place in the arterial smooth muscle at the origin of the collateral vasculature.

Vasomotor responses of newly developed coronary collateral vessels

1996 ◽  
Vol 271 (2) ◽  
pp. H490-H497 ◽  
Author(s):  
J. W. Kinn ◽  
J. D. Altman ◽  
M. W. Chang ◽  
R. J. Bache
Keyword(s):  
Nitric Oxide ◽  
Blood Flow ◽  
Coronary Artery ◽  
Retrograde Flow ◽  
Collateral Blood Flow ◽  
Coronary Collateral ◽  
Retrograde Blood Flow ◽  
Vasomotor Activity ◽  
Collateral Vessels ◽  
Oxide Synthase

Well-developed coronary collateral vessels contain an abundant muscular media and can undergo active vasomotion. However, early after coronary occlusion, coronary collateral vessels are thin walled with little smooth muscle, suggesting that vasomotor capability might be limited. Consequently, this study determined whether newly developed coronary collateral vessels have active vasomotor activity and whether endothelial function in these newly developed vessels is impaired. Retrograde blood flow was measured as an index of coronary collateral blood flow approximately 2 wk after embolic occlusion of the anterior descending coronary artery of dogs. Agonists were administered into the left main coronary artery to reach collaterals originating from the left coronary system. Baseline retrograde blood flow was 25.1 +/- 2.7 ml/min and increased to 36.7 +/- 3.7 ml/min after nitroglycerin (6 micrograms.kg-1.min-1, P < 0.05). Cyclooxygenase blockade with indomethacin (5 mg/kg i.v.) decreased retrograde collateral blood flow to 16.8 +/- 2.3 ml/min (P <a 0.05). Subsequent administration of acetylcholine increased retrograde flow to 29.4 +/- 3.7 ml/min (P < 0.05), indicating intact endothelium-mediated vasodilation. Inhibition of nitric oxide synthase with NG-nitro-L-arginine further decreased coronary collateral retrograde flow to 12.0 +/- 2.8 ml/min (P < 0.05) and markedly blunted the response to acetylcholine. These findings demonstrate substantial vasomotor capability even early during coronary collateral development and indicate that both nitric oxide and cyclooxygenase-dependent endothelial mechanisms are intact.

Thrombosis in one coronary artery causes generalized coronary vasoconstriction in a dog model of unstable angina

2001 ◽  
Vol 100 (4) ◽  
pp. 405-410 ◽  
Author(s):  
Mohammed MANSARAY ◽  
John W. HYND ◽  
Isobel VERGROESEN ◽  
Philip R. BELCHER ◽  
Angela J. DRAKE-HOLLAND ◽  
...  
Keyword(s):  
Blood Flow ◽  
Coronary Artery ◽  
Unstable Angina ◽  
Vascular Resistance ◽  
General Circulation ◽  
Venous Pressure ◽  
Time Control ◽  
Vascular Bed ◽  
Coronary Sinus Catheter ◽  
Collateral Vessels

We investigated the effect of thrombosis in one coronary artery upon the vascular resistance of another coronary artery. In previous investigations, using an animal model of unstable angina, we have observed increased resistance downstream from thrombus within a left circumflex coronary artery (LCx) stenosis and vasoconstriction of collateral vessels from the left anterior descending artery (LAD) supplying the distal LCx vascular bed. In the present paper, we induced thrombosis within a stenosis of the LCx of 16 beagle dogs, and observed the changes in blood flow to the myocardium supplied by the LAD using the radioactive microsphere technique. This blood flow decreased with thrombosis (P = 0.005) in these animals, whereas it did not do so in three time-control experiments. The pressures across the coronary vascular bed, i.e. arterial pressure to coronary venous pressure (coronary sinus catheter), did not change. Thus the vascular resistance of the LAD bed increased significantly from 147±ll.5 mmHg/ml/sec/g of tissue to 172±13.4 mmHg/ml/sec/g of tissue (P = 0.02). As the LAD territory is not perfused with blood from the artery containing thrombus, we conclude that the effect observed is caused either by release of vasoconstrictors from the thrombus into the general circulation, or by activation of a neural reflex vasoconstriction. The study suggests that unstable angina involving thrombosis in one coronary artery is a global coronary vascular disease.

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