Exercise-induced ST-segment changes permit prediction of improvement in left ventricular ischemic dysfunction after revascularization: Evaluation with positron emission tomographic measurements of regional myocardial blood flow and cardiac output*1

1998 ◽  
Vol 5 (3) ◽  
pp. 256-264 ◽  
Author(s):  
T WATANABE
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Myocardial Blood Flow ◽  
Left Ventricular ◽  
Regional Myocardial Blood Flow ◽  
Positron Emission Tomographic ◽  
Positron Emission ◽  
St Segment ◽  
Exercise Induced ◽  
Regional Myocardial Blood

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.

Sign in / Sign up

Export Citation Format

Share Document