Regional myocardial blood flow and glucose utilization during fasting and physiological hyperinsulinemia in humans

2002 ◽  
Vol 282 (5) ◽  
pp. E1163-E1171 ◽  
Author(s):  
Patricia Iozzo ◽  
Panithaya Chareonthaitawee ◽  
Marco Di Terlizzi ◽  
D. John Betteridge ◽  
Ele Ferrannini ◽  
...  
Keyword(s):  
Blood Flow ◽  
Myocardial Blood Flow ◽  
Healthy Subjects ◽  
Regional Distribution ◽  
Lateral Wall ◽  
Left Ventricular ◽  
Regional Myocardial Blood Flow ◽  
Positron Emission ◽  
Normal Human ◽  
Regional Myocardial Blood

We investigated the effect of insulin on total and regional myocardial blood flow (MBF) and glucose uptake (MGU) in healthy subjects (50 ± 5 yr) by means of positron emission tomography (PET) with oxygen-15-labeled water (H2 15O) and fluorine-18 labeled fluorodeoxyglucose (18FDG) before and during physiological hyperinsulinemia (40 mU · min−1 · m−2). Twelve male subjects were included in the study. During hyperinsulinemia, MBF increased from 0.91 ± 0.28 to 1.01 ± 0.31 ml · min−1 · g−1 ( n= 7 patients, P = 0.05; n = 112 regions, P < 0.005). Intersubject variability ranged from −3.0 to +41%. MGU increased from 0.11 ± 0.08 ( n = 5) to 0.56 ± 0.08 μmol · min−1 · g−1( P < 0.0001, n = 7). MBF and insulin-mediated MGU were higher in the septum and anterior and lateral wall along short-axis regions of the heart. During hyperinsulinemia, MBF was also higher in the apex and midventricle compared with the base. MBF and MGU were positively correlated before ( r = 0.66, P < 0.0001) and during hyperinsulinemia ( r= 0.24, P < 0.05). These results provide evidence that insulin stimulates MBF in normal human hearts and appears to involve mainly those regions of the heart where insulin-mediated MGU is higher. Furthermore, regional distribution of insulin-stimulated MBF and MGU does not appear to be uniform across the left ventricular wall of healthy subjects.

Measurement of regional myocardial blood flow in rats by unlabeled microspheres and Coulter channelyzer

1996 ◽  
Vol 271 (4) ◽  
pp. H1656-H1665
Author(s):  
X. Wang ◽  
F. Li ◽  
S. Said ◽  
J. M. Capasso ◽  
A. M. Gerdes
Keyword(s):  
Blood Flow ◽  
Myocardial Blood Flow ◽  
Cardiac Tissue ◽  
Ex Vivo ◽  
Left Ventricular ◽  
Regional Myocardial Blood Flow ◽  
Blood Samples ◽  
Flow Gradients ◽  
Transmural Flow ◽  
Regional Myocardial Blood

A relatively inexpensive, expeditious, new nonradioactive microsphere method for measuring regional myocardial blood flow (RMBF) was developed with unlabeled microspheres and a Coulter Channelyzer. To validate the efficiency of this method, hearts from rats were perfused ex vivo by retrograde aortic cannulation. Unlabeled microspheres of varying size were injected into a side arm in the aortic cannula or added to blood samples collected from the rats. Microspheres were then recovered from the cardiac tissue and blood samples. It was found that > 97% of perfused microspheres (diam > 9.4 microns) were retained in the myocardium and that 94.8 +/- 2.2% of the trapped microspheres were recovered and counted successfully using a Counter Channelyzer. The percent recovery of microspheres from 2- and 0.5-ml blood samples were 95.4 +/- 2.3 and 95.3 +/- 3.1%, respectively. Blood flow to the anterior and posterior halves of the ventricular free walls and septum were measured in six rats; excellent agreements were found between the results yielded by 10-, 15-, and 20-microns unlabeled microspheres injected simultaneously. The transmural flow gradients in the left ventricular free wall estimated by 10- and 15-microns spheres did not significantly differ from each other. Thus the method developed here provides a new alternative for measurement of RMBF, which currently allows at least three measurements for nontransmural gradient RMBF and at least two measurements for transmural gradient RMBF.

Depression of regional blood flow and wall thickening after brief coronary occlusions

1978 ◽  
Vol 234 (6) ◽  
pp. H653-H659 ◽  
Author(s):  
G. R. Heyndrickx ◽  
H. Baig ◽  
P. Nellens ◽  
I. Leusen ◽  
M. C. Fishbein ◽  
...  
Keyword(s):  
Blood Flow ◽  
Myocardial Blood Flow ◽  
Coronary Occlusion ◽  
Reactive Hyperemia ◽  
Left Ventricular ◽  
Regional Myocardial Blood Flow ◽  
Wall Thickening ◽  
Flow Ratio ◽  
Systolic Wall Thickening ◽  
Regional Myocardial Blood

The effects of a 15-min coronary occlusion and subsequent reperfusion were investigated in conscious dogs previously instrumented for measurement of left ventricular pressure, dP/dt, regional wall thickening, electrograms, and myocardial blood flow. Coronary occlussion reduced overall left ventricular function only slightly but eliminated systolic wall thickening in the ischemic zone and reduced regional myocardial blood flow in the ischemic zone from 1.04 +/- 0.04 to 0.27 +/- 0.02 ml/min per g and the endo/epi flow ratio from 1.23 +/- 0.04 to 0.44 +/- 0.04, while S-T segment elevation increased from 1.1 +/- 0.3 to 8.2 +/- 0.9 mV. After release of the occlusion, S-T segment elevation disappeared within 1 min while reactive hyperemia in the previously occluded artery and a transient increase in cardiac diastolic wall thickness occurred and then subsided by 15 min. In contrast, systolic wall thickening and the endo/epi flow ratio remained significantly depressed for more than 3 h. Thus reperfusion after a 15 minute coronary occlusion results in a prolonged period of reduced regional myocardial blood flow, particularly in the endocardial layers, which correlates with the prolonged depression of regional myocardial shortening and wall thickening.

scholarly journals Modeling regional myocardial flows from residue functions of an intravascular indicator

1996 ◽  
Vol 271 (4) ◽  
pp. H1643-H1655 ◽  
Author(s):  
K. Kroll ◽  
N. Wilke ◽  
M. Jerosch-Herold ◽  
Y. Wang ◽  
Y. Zhang ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Blood Flow ◽  
Magnetic Resonance ◽  
Myocardial Blood Flow ◽  
Left Ventricular ◽  
Regional Myocardial Blood Flow ◽  
Resonance Imaging ◽  
Vascular Volume ◽  
Regional Flow ◽  
Regional Myocardial Blood

The purpose of the present study was to determine the accuracy and the sources of error in estimating regional myocardial blood flow and vascular volume from experimental residue functions obtained by external imaging of an intravascular indicator. For the analysis, a spatially distributed mathematical model was used that describes transport through a multiple-pathway vascular system. Reliability of the parameter estimates was tested by using sensitivity function analysis and by analyzing “pseudodata”: realistic model solutions to which random noise was added. Increased uncertainty in the estimates of flow in the pseudodata was observed when flow was near maximal physiological values, when dispersion of the vascular input was more than twice the dispersion of the microvascular system for an impulse input, and when the sampling frequency was < 2 samples/s. Estimates of regional blood volume were more reliable than estimates of flow. Failure to account for normal flow heterogeneity caused systematic underestimates of flow. To illustrate the method used for estimating regional flow, magnetic resonance imaging was used to obtain myocardial residue functions after left atrial injections of polylysine-Gd-diethylenetriaminepentaacetic acid, an intravascular contrast agent, in anesthetized chronically instrumental dogs. To test the increase in dispersion of the vascular input after central venous injections, magnetic resonance imaging data obtained in human subjects were compared with left ventricular blood pool curves obtained in dogs. It is concluded that if coronary flow is in the normal range, when the vascular input is a short bolus, and the heart is imaged at least once per cardiac cycle, then regional myocardial blood flow and vascular volume may be reliably estimated by analyzing residue functions of an intravascular indicator, providing a noninvasive approach with potential clinical application.

scholarly journals Regional myocardial blood flow and left ventricular diastolic properties in pacing-induced ischemia

1991 ◽  
Vol 17 (3) ◽  
pp. 781-789 ◽  
Author(s):  
Shin-Ichi Momomura ◽  
James J. Ferguson ◽  
Michael J. Miller ◽  
J. Anthony Parker ◽  
William Grossman
Keyword(s):  
Blood Flow ◽  
Myocardial Blood Flow ◽  
Left Ventricular ◽  
Regional Myocardial Blood Flow ◽  
Diastolic Properties ◽  
Regional Myocardial Blood
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