Analysis of coronary collateral structure, function, and ischemic border zones in pigs

1983 ◽  
Vol 244 (1) ◽  
pp. H23-H31 ◽  
Author(s):  
R. E. Patterson ◽  
E. S. Kirk
Keyword(s):  
Blood Flow ◽  
Myocardial Blood Flow ◽  
Left Ventricular ◽  
Border Zone ◽  
Homogeneous Distribution ◽  
Collateral Blood Flow ◽  
Lateral Border ◽  
Coronary Collateral ◽  
Border Zones ◽  
And Function

The purpose of this study was to compare coronary collateral structure and function in pigs with those in dogs and to analyze the distribution of collateral blood flow across the lateral and transmural border zones in the pig. After acute occlusion of the left anterior descending coronary artery (LAD) in 26 anesthetized open-chest pigs, minimal collateral blood flow was indicated by retrograde flow (0.2 +/- 0.1 ml/min) and microsphere-myocardial blood flow (0.005 +/- 0.001 ml X min-1g-1). Postmortem injection of the distal LAD followed by clearance of the heart demonstrated few tiny collateral structures and negligible collateral filling of other arteries. In contrast to dogs, pigs showed no measurable gradient of collateral blood flow across the transmural border zone, and pigs showed no change in collateral blood flow or its transmural distribution during retrograde drainage of collateral blood flow or elevated left ventricular filling pressures. Pigs showed higher myocardial blood flow in the lateral border than in the center of the ischemic zone. As in the dog, however, this gradient of blood flow across the lateral border zone was accounted for by overlap between occluded LAD branches and unoccluded coronary arterial branches rather than by preferential collateral perfusion of the lateral border of the ischemic zone. We conclude that the pig has a homogeneous distribution of collateral blood flow across the transmural and lateral border zones after acute coronary occlusion but that the minimal collateral circulation limits the usefulness of the pig as a model of ischemic heart disease.

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.

Regional Deficits of Myocardial Blood Flow and Function in Left Ventricular Pacing–Induced Heart Failure

Circulation ◽  
1996 ◽  
Vol 94 (9) ◽  
pp. 2260-2267 ◽  
Author(s):  
Gregory A. Helmer ◽  
M. Dan McKirnan ◽  
Ralph Shabetai ◽  
Gerry R. Boss ◽  
John Ross ◽  
...  
Keyword(s):  
Heart Failure ◽  
Blood Flow ◽  
Myocardial Blood Flow ◽  
Left Ventricular ◽  
Ventricular Pacing ◽  
Left Ventricular Pacing ◽  
Regional Deficits ◽  
And Function

Effect of repeated episodes of reversible myocardial ischemia on myocardial blood flow and function in humans

2002 ◽  
Vol 282 (5) ◽  
pp. H1603-H1608 ◽  
Author(s):  
Edward Barnes ◽  
David P. Dutka ◽  
Masood Khan ◽  
Paolo G. Camici ◽  
Roger J. Hall
Keyword(s):  
Blood Flow ◽  
Coronary Artery ◽  
Myocardial Blood Flow ◽  
Systolic Function ◽  
Peak Stress ◽  
Left Ventricular ◽  
Lv Function ◽  
Positron Emission ◽  
Artery Disease ◽  
And Function

Nine patients with coronary artery disease and normal left ventricular (LV) function underwent two episodes of dobutamine-induced ischemia to determine whether repeated episodes of ischemia lead to cumulative stunning. Positron emission tomography (PET) and oxygen 15-labeled H2O was used to assess myocardial blood flow (MBF) at baseline, peak stress, and after stress for each ischemic episode. Quantitative echocardiographic assessment of global ejection fraction (EF) and regional systolic function (SF) was performed at rest and regular intervals after dobutamine. SF was assessed for regions subtended by a coronary artery with a >70% diameter stenosis. Both EF and SF were more severely impaired 45 min after the second episode of stress compared with 45 min after the first (both P < 0.01), despite no difference in duration of the two dobutamine infusions or MBF at peak stress (1.72 vs. 1.69). After both episodes of ischemia, when LV function was impaired but subsequently recovered, MBF (1.15 ± 0.39 and 1.20 ± 0.43, respectively) was no different to baseline MBF (1.02 ± 0.35), confirming that repeated episodes of dobutamine-induced ischemia lead to cumulative myocardial stunning.

The influence of nifedipine on myocardial blood flow in the ischemic and lateral border zones

1981 ◽  
Vol 47 ◽  
pp. 442 ◽  
Author(s):  
William S. Weintraub ◽  
Shigehiko Hattori ◽  
Jai B. Agarwal ◽  
Monty M. Bodenheimer ◽  
Vidya S. Banka ◽  
...  
Keyword(s):  
Blood Flow ◽  
Myocardial Blood Flow ◽  
Lateral Border ◽  
Border Zones

Regional myocardial blood flow and necrosis in primates following coronary occlusion

1984 ◽  
Vol 246 (4) ◽  
pp. H635-H639 ◽  
Author(s):  
M. Lavallee ◽  
S. F. Vatner
Keyword(s):  
Blood Flow ◽  
Coronary Artery ◽  
Myocardial Blood Flow ◽  
Coronary Occlusion ◽  
Coronary Artery Occlusion ◽  
Artery Occlusion ◽  
Border Zone ◽  
Regional Myocardial Blood Flow ◽  
Lateral Border ◽  
Regional Myocardial Blood

The effects of acute coronary artery occlusion on regional myocardial blood flow distribution in the remote nonischemic zone, the central ischemic zone, and the lateral border zone of the infarct were evaluated in conscious primates. Prior to coronary artery occlusion, blood flow was 1.51 +/- 0.11 in endocardial (Endo) and 1.36 +/- 0.11 ml X min-1g-1 in epicardial (Epi) layers with an Endo-to-Epi ratio of 1.17 +/- 0.05. Regional blood flow in the remote nonischemic zone increased by 28.0 +/- 4.7 and 31.7 +/- 3.6% for Endo and Epi layers, respectively, following coronary occlusion and remained elevated during the subsequent 24 h. At the center of infarct, Endo and Epi blood flows were depressed by 97.9 +/- 0.7 and by 97.9 +/- 0.8%, respectively, at 5 min after coronary occlusion and remained severely depressed throughout the 24-h observation period. Blood flow at the ischemic lateral border of the infarct was severely depressed and similar to the flow at the center of the infarct, whereas the nonischemic lateral border of the infarct had blood flow levels similar to the remote, nonischemic myocardium. Microsphere loss was not a feature of the primate infarct.

Coronary collateral stimulation by exercise in dogs with stenotic coronary arteries

1982 ◽  
Vol 52 (3) ◽  
pp. 664-671 ◽  
Author(s):  
M. V. Cohen ◽  
T. Yipintsoi ◽  
J. Scheuer
Keyword(s):  
Blood Flow ◽  
Myocardial Blood Flow ◽  
Left Atrial ◽  
Reactive Hyperemia ◽  
Left Ventricular ◽  
Treadmill Running ◽  
Collateral Flow ◽  
Flow Measurements ◽  
Collateral Development ◽  
Coronary Collateral

To determine the effects of an exercise-training program on coronary collateral development, we instrumented 13 1-yr-old beagles with left circumflex (LCf) coronary artery flow probes and balloon occluders and left atrial and aortic catheters. The LCf artery was constricted resulting in a 58 +/- 4% reduction of the peak reactive hyperemia response following release of a 154-s LCf occlusion. All dogs were studied during the first week of the study protocol. Resting heart rate, cardiac output, and left atrial and aortic pressures were evaluated before and during a 1-min LCf occlusion. Myocardial blood flow was also measured with radioactively-labeled microspheres injected into the left atrium during the LCf occlusion. Subsequently the dogs were exercised at 6.4 km/h and 12% grade, and all hemodynamic and blood flow measurements were repeated. The animals were then randomized to either a sedentary or exercising group. The six sedentary animals were confined to their cages, while the seven training beagles did sprint and endurance running for 75 min/day, 5 days/wk. After 12 wk the hemodynamic and blood flow studies were repeated at rest and during treadmill running. There were no statistically significant differences in resting or exercise hemodynamics, response to LCf occlusion, or myocardial blood flow in the two groups in wk 1. Hemodynamics and blood flow data were virtually unchanged in the sedentary animals after 12 wk. However, the trained dogs demonstrated less evidence of left ventricular failure following LCf occlusion while running and had significantly higher myocardial blood flows. Their resting collateral flow increased from 0.52 +/- 0.16 ml . min-1 . g-1 at wk 1 to 0.90 +/- 0.28 ml . min-1 . g-1 at wk 12 (P less than 0.05), while the ratio of collateral to normal myocardial blood flow increased from 0.46 +/- 0.12 to 0.64 +/- 0.16 (P less than 0.05). Thus chronic exercise can stimulate coronary collateral development, and the enhanced collateral flow has a salutary functional effect.

An approach for comparative quantification of myocardial blood flow (0-15-H2O-PET), perfusion (Tc-99m-tetrofosmin-SPECT), and metabolism (F 18-FDG-PET)

2001 ◽  
Vol 40 (05) ◽  
pp. 164-171 ◽  
Author(s):  
B. Nowak ◽  
H.-J. Kaiser ◽  
S. Block ◽  
K.-C. Koch ◽  
J. vom Dahl ◽  
...  
Keyword(s):  
Blood Flow ◽  
Myocardial Blood Flow ◽  
Fdg Pet ◽  
Model Fitting ◽  
Compartment Model ◽  
Left Ventricular ◽  
Short Axis ◽  
New Approach ◽  
Single Compartment Model ◽  
Tissue Fraction

Summary Aim: In the present study a new approach has been developed for comparative quantification of absolute myocardial blood flow (MBF), myocardial perfusion, and myocardial metabolism in short-axis slices. Methods: 42 patients with severe CAD, referred for myocardial viability diagnostics, were studied consecutively with 0-15-H2O PET (H2O-PET) (twice), Tc-99m-Tetrofosmin 5PECT (TT-SPECT) and F-18-FDG PET (FDG-PET). All dato sets were reconstructed using attenuation correction and reoriented into short axis slices. Each heart was divided into three representative slices (base, rnidventricular, apex) and 18 ROIs were defined on the FDG PET images and transferred to the corresponding H2O-PET and TT-SPECT slices. TT-SPECT and FDG-PET data were normalized to the ROI showing maximum perfusion. MBF was calculated for all left-ventricular ROIs using a single-compartment-model fitting the dynamic H2O-PET studies. Microsphere equivalent MBF (MBF_micr) was calculated by multiplying MBF and tissue-fraction, a parameter which was obtained by fitting the dynamic H2O-PET studies. To reduce influence of viability only well perfused areas (>70% TT-SPECT) were used for comparative quantification. Results: First and second mean global MBF values were 0.85 ml × min-1 × g-1 and 0.84 ml × min-1 × g1, respectively, with a repeatability coefficient of 0.30 ml ÷ min-1 × gl. After sectorization mean MBF_micr was between 0.58 ml × min1 ÷ ml"1 and 0.68 ml × min-1 × ml"1 in well perfused areas. Corresponding TT-SPECT values ranged from 83 % to 91 %, and FDG-PET values from 91 % to 103%. All procedures yielded higher values for the lateral than the septal regions. Conclusion: Comparative quantification of MBF, MBF_micr, TT-SPECT perfusion and FDG-PET metabolism can be done with the introduced method in short axis slices. The obtained values agree well with experimentally validated values of MBF and MBF_micr.

Myocardial blood flow determined with krypton 85 in unanesthetized dogs

1962 ◽  
Vol 203 (1) ◽  
pp. 122-124 ◽  
Author(s):  
J. A. Herd ◽  
M. Hollenberg ◽  
G. D. Thorburn ◽  
H. H. Kopald ◽  
A. C. Barger
Keyword(s):  
Blood Flow ◽  
Coronary Artery ◽  
Myocardial Blood Flow ◽  
Exponential Function ◽  
Scintillation Detector ◽  
Left Ventricular ◽  
Blood Flows ◽  
Single Exponential Function ◽  
Single Exponential ◽  
Rapid Measurements

Serial, rapid measurements of left ventricular myocardial blood flow in trained, unanesthetized dogs have been made by injecting krypton 85 through chronically implanted coronary artery catheters and counting with an external scintillation detector. Precordial radioactivity declined as a single exponential function during the first 2 min after injection, suggesting a single rate of myocardial blood flow. Simultaneous estimations with Kr85 and blood flowmeters in acute experiments established the accuracy and reproducibility of the technique. Myocardial blood flows between 40 and 55 ml/100 g/min were observed repeatedly in three well-trained, unanesthetized dogs in the basal state.

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