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.

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

scholarly journals Effects of Adenosine and 2-Chloroadenosine on Cerebral Collateral Vessels

1995 ◽  
Vol 15 (6) ◽  
pp. 1075-1081 ◽  
Author(s):  
Michael G. Muhonen ◽  
Christopher M. Loftus ◽  
Donald D. Heistad
Keyword(s):  
Blood Flow ◽  
Cerebral Artery ◽  
Topical Application ◽  
Collateral Circulation ◽  
Arterial Occlusion ◽  
Collateral Flow ◽  
Cortical Layers ◽  
Area At Risk ◽  
Collateral Vessels ◽  
Cerebral Vasodilator

Adenosine is a potent cerebral vasodilator. We tested the hypothesis that dilatation of collateral vessels in cerebrum, in response to topical adenosine and 2-chloroadenosine (2-CAD), would increase blood flow to collateral-dependent cerebrum. In dogs anesthetized with halothane, a branch of the middle cerebral artery (MCA) was occluded proximally and cannulated distally. The collateral-dependent area at risk for infarction was perfused from a reservoir with microsphere-free blood, and blood flow to normal cerebrum and to cerebrum dependent on collateral flow was measured with radioactive microspheres injected into the left ventricle through a femoral artery catheter. Perfusion through the cannulated MCA branch was stopped, and flow to normal and collateral-dependent cerebrum was measured after adenosine (10−2 M) or 2-CAD (10−4 M) was added to the superfusate over the cerebrum. In normal cerebrum, topical application of adenosine increased flow to outer but not inner layers. Topical application of adenosine had little effect on flow to collateral-dependent tissue. In normal cerebrum, 2-CAD increased flow to outer layers, whereas flow to inner layers tended to increase. During 2-CAD, flow to outer cortical layers of collateral-dependent cerebrum increased from 140 ± 20 ml/100 g/min (mean ± SD) to 231 ± 68, whereas flow to the inner collateral-dependent tissue did not change. The findings indicate that, after occlusion of a cerebral artery, topical 2-CAD increases blood flow to outer layers of collateral-dependent and normal cerebrum. The findings suggest also that, after arterial occlusion, collateral circulation to cerebrum has dilator reserve, and flow to tissues that are dependent on collaterals may be augmented.

scholarly journals AN ELECTROGRAPHIC STUDY ON THE FUNCTIONAL CAPACITY OF THE CORONARY COLLATERAL CIRCULATION IN DOGS WITH CHRONIC CORONARY OCCLUSION

1980 ◽  
Vol 44 (4) ◽  
pp. 294-302 ◽  
Author(s):  
YUTAKA KATADA ◽  
TETSUO MIZUTANI ◽  
KISHIO MAEKAWA ◽  
TAKAYOSHI AZUMI ◽  
KATSUAKI FUJIWARA ◽  
...  
Keyword(s):  
Functional Capacity ◽  
Collateral Circulation ◽  
Coronary Occlusion ◽  
Coronary Collateral Circulation ◽  
Coronary Collateral ◽  
Chronic Coronary Occlusion

Effect of physical training on coronary collateral circulation of the rat

1982 ◽  
Vol 52 (2) ◽  
pp. 376-387 ◽  
Author(s):  
J. E. Koerner ◽  
R. L. Terjung
Keyword(s):  
Blood Flow ◽  
Physical Training ◽  
Collateral Circulation ◽  
Diastolic Pressure ◽  
Left Ventricular ◽  
Border Zone ◽  
Coronary Collateral Circulation ◽  
Coronary Collateral ◽  
Border Zones ◽  
Wide Range

The influence of physical training on coronary collateral circulation following acute ligation of the left coronary artery was determined in pentobarbital-anesthetized rats. Coronary blood flows were determined with 15-microns microspheres during a wide range of perfusion pressures and during adenosine infusion. The demarcation between normal and ischemic tissue was achieved using nitroblue tetrazolium strain and thioflavin S fluorescence. Contractile performance was not altered by training, with the exception of a lower left ventricular end-diastolic pressure when afterload was elevated. Blood flow to and the size of the central ischemic zone were not influenced by training. However, in border zones, where collateral dependent flow is expected to be most pronounced, blood flow as a percent of normal was increased (16%, P less than 0.02) in trained animals. This increased was abolished by coronary vasodilation with adenosine. These results indicate that training caused a limited increase in collateral blood flow to the border zone. Further, tissue reactivity to adenosine following short periods of ischemia is normal in trained rats but decreased in border (11%) and ischemic (21%, P less than 0.05) zones in sedentary rats. Whether his small increase in blood flow to the border tissue, along with a retained capacity for dilatation, could lead to an improved salvage of tissue remains to be evaluated.

Comparison of the coronary collateral circulation in dogs and baboons after coronary occlusion

1976 ◽  
Vol 92 (2) ◽  
pp. 193-200 ◽  
Author(s):  
Allen B. Weisse ◽  
Katherine Kearney ◽  
Ravinder M. Narang ◽  
Timothy J. Regan
Keyword(s):  
Collateral Circulation ◽  
Coronary Occlusion ◽  
Coronary Collateral Circulation ◽  
Coronary Collateral

Abstract 2716: Patients with Leukoaraiosis Have Poor Recruitment of Collaterals After Middle Cerebral Artery Occlusion

Stroke ◽  
2012 ◽  
Vol 43 (suppl_1) ◽  
Author(s):  
Ethem Murat Arsava ◽  
Osman Melih Topcuoglu ◽  
Erhan Akpinar ◽  
Kader K Oguz ◽  
Mehmet Akif Topcuoglu
Keyword(s):  
Blood Flow ◽  
Ischemic Stroke ◽  
Middle Cerebral Artery ◽  
Middle Cerebral Artery Occlusion ◽  
Cerebral Artery ◽  
Collateral Circulation ◽  
Artery Occlusion ◽  
Poor Recruitment ◽  
Collateral Vessels ◽  
Cerebral Artery Occlusion

Background: Previous studies have shown reduced penumbral salvage in ischemic stroke patients with higher leukoaraisosis (LA) volume. Although unproven, decreased cerebral vessel density and diminished capacity of cerebral vessels to dilate in response to reduced blood flow in severe LA, are considered among the factors that might explain the association between LA burden and infarct growth in ischemic stroke. Both of these factors, in theory, might negatively affect the extent of collateral blood flow, an important predictor of tissue and clinical outcome in patients with acute ischemic stroke. In this study, we therefore analyzed whether extent of LA adversely affected the degree of collateral circulation in a cohort of patients presenting with middle cerebral artery occlusion. Methods: We retrospectively analyzed a consecutive series of patients admitted with a diagnosis of middle cerebral artery occlusion. Computed tomography angiography source images (CTA-SI) were used to assess the degree of collateral circulation, based on a previously validated scoring system which grades collateral vessels in the sylvian fissure and leptomeningeal convexity separately on a scale from 1 to 5, with 1 being the worst and 5 the best. The extent of LA was determined on FLAIR images by using the Fazekas scale. Multivariate analysis was used to explore the relationship between extent of LA and degree of collateral circulation, adjusted for other covariates like age, gender, vascular risk factors and time from symptom onset to CTA imaging. Results: A total of 51 patients (31 female, 20 male) were included into the study. LA severity was significantly and negatively correlated with the degree of collateral supply (r=-0.31, p=0.03). LA severity (OR 5.9, 95%CI 1.5-24.0) and history of prior stroke (OR 7.8, 95%CI 1.0-59.3) were the only significant variables associated with insufficient collaterals (defined as a combined sylvian and lepotmeningeal collateral score of 5 or less) in the multivariate logistic regression analysis. Conclusion: Patients with higher LA burden have a poor recruitment of collateral vessels after middle cerebral artery occlusion. This association might contribute to reduced penumbral salvage and increased susceptibility to infarct growth observed in patients with severe LA.

scholarly journals Coronary Collateral Circulation and Myocardial Blood Flow Reserve

Circulation ◽  
1972 ◽  
Vol 46 (1) ◽  
pp. 84-94 ◽  
Author(s):  
SUZANNE B. KNOEBEL ◽  
PAUL L. MCHENRY ◽  
JOHN F. PHILLIPS ◽  
FEBREL J. PAULETTO
Keyword(s):  
Blood Flow ◽  
Myocardial Blood Flow ◽  
Collateral Circulation ◽  
Coronary Collateral Circulation ◽  
Coronary Collateral ◽  
Flow Reserve ◽  
Myocardial Blood Flow Reserve

Vasospasm and Regional Cerebral Blood Flow (rCBF) in Patients with Ruptured Intracranial Aneurysm: Serial rCBF Studies with the Xenon-133 Inhalation Method

Neurosurgery ◽  
1983 ◽  
Vol 13 (4) ◽  
pp. 394-401 ◽  
Author(s):  
Iwao Yamakami ◽  
Katsumi Isobe ◽  
Akira Yamaura ◽  
Takao Nakamura ◽  
Hiroyasu Makino
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Neurological Deficit ◽  
Mean Value ◽  
Initial Slope ◽  
Delayed Ischemic Neurological Deficit ◽  
Ruptured Intracranial Aneurysm ◽  
The Mean ◽  
Xenon 133 ◽  
Head Probe

Abstract To clarify the relationship of vasospasm to the reduction of cerebral blood flow (CBF) and the delayed ischemic neurological deficit, serial rCBF studies with the use of the xenon-133 inhalation method were conducted in 35 postoperative patients with ruptured intracranial aneurysms. The CBF was calculated as an initial slope index (ISI) derived from the desaturation curve of each head probe, and the hemispheric mean value of the ISI (mean ISI) was calculated in both hemispheres. The mean ISI in the hemisphere ipsilateral to the operation was low compared to that of the contralateral hemisphere. In relation to the presence of vasospasm, angiographic findings were classified into the following five types: diffuse, peripheral, proximal-severe, proximal-mild, and no spasm. Patients with vasospasm of the diffuse, peripheral, and proximal-severe types showed a markedly decreased mean ISI, and vasospasm of the diffuse type caused the greatest degree of reduction. The mean ISI of the patients who developed delayed ischemic neurological deficit (DIND) due to vasospasm was significantly decreased (37.4± 4.6) compared to that of the patients who did not develop DIND (52.2± 5.6). None of 3 cases of no spasm and only 1 of 14 cases of proximal-mild spasm developed DIND. On the other hand, all of 4 cases of diffuse, 2 of 3 cases of peripheral, and 2 of 6 cases of proximal-severe spasm developed DIND. Thus, if these three types of vasospasm are joined together as severe vasospasm, 8 of 13 cases with severe vasospasm developed DIND. These results suggest that severe vasospasm causes a reduction of CBF and that the reduced CBF brings about DIND.

The mean value of the fluctuations in pressure and pressure gradient in a turbulent fluid

1936 ◽  
Vol 32 (3) ◽  
pp. 380-384 ◽  
Author(s):  
G. I. Taylor
Keyword(s):  
Pressure Gradient ◽  
Mean Value ◽  
Turbulent Fluid ◽  
General Systems ◽  
The Mean ◽  
Image Position

In the general systems of vortices represented by (1) the mean variation in pressureiswhereKis a number which varies between 1 and √2. When the vortices are confined to cubical partitions, the case most nearly analogous to that of free turbulence,K= 1·06, so that the conjecture which I made some years ago, thatwould be equal tois probably nearly correct.

Sign in / Sign up

Export Citation Format

Share Document