Effects of gestational age on myocardial blood flow and coronary flow reserve in pressure-loaded ovine fetal hearts

2002 ◽  
Vol 282 (4) ◽  
pp. H1359-H1369 ◽  
Author(s):  
Gregory B. Dalshaug ◽  
Thomas D. Scholz ◽  
Oliva M. Smith ◽  
Kurt A. Bedell ◽  
Christopher A. Caldarone ◽  
...  
Keyword(s):  
Blood Flow ◽  
Pulmonary Artery ◽  
Myocardial Blood Flow ◽  
Coronary Flow Reserve ◽  
Coronary Flow ◽  
Left Ventricular ◽  
Mrna Levels ◽  
Blood Flows ◽  
Flow Reserve ◽  
Arterial Blood

To test the hypothesis that coronary flow and coronary flow reserve are developmentally regulated, we used fluorescent microspheres to investigate the effects of acute (6 h) pulmonary artery banding (PAB) on baseline and adenosine-enhanced right (RV) and left ventricular (LV) blood flow in two groups of twin ovine fetuses (100 and 128 days of gestation, term 145 days, n = 6 fetuses/group). Within each group, one fetus underwent PAB to constrict the main pulmonary artery diameter by 50%, and the other twin served as a nonbanded control. Physiological measurements were made 6 h after the surgery was completed; tissues were then harvested for analysis of selected genes that may be involved in the early phase of coronary vascular remodeling. Within each age group, arterial blood gas values, heart rate, and mean arterial blood pressure were similar between control and PAB fetuses. Baseline endocardial blood flow in both ventricles was greater in 100 than 128-day fetuses (RV: 341 ± 20 vs. 230 ± 17 ml · min−1 · 100 g−1; LV: 258 ± 18 vs. 172 ± 23 ml · min−1 · 100 g−1, both P < 0.05). In both age groups, RV and LV endocardial blood flows increased significantly in control animals during adenosine infusion and were greater in PAB compared with control fetuses. After PAB, adenosine further increased RV blood flow in 128-day fetuses (from 416 ± 30 to 598 ± 33 ml · min−1 · 100 g−1, P < 0.05) but did not enhance blood flow in 100-day animals (490 ± 59 to 545 ± 42 ml · min−1 · 100 g−1, P > 0.2). RV vascular endothelial growth factor and Flk-1 mRNA levels were increased relative to controls ( P < 0.05) in 128 but not 100-day PAB fetuses. We conclude that in the ovine fetus, developmentally related differences exist in 1) baseline myocardial blood flows, 2) the adaptive response of myocardial blood flow to acute systolic pressure load, and 3) the responses of selected genes involved in vasculogenesis to increased load in the fetal myocardium.

scholarly journals Positron emission tomography application for myocardial blood flow and coronary flow reserve measurement in patients with cardiovascular pathology

2006 ◽  
Vol 12 (3) ◽  
pp. 200-211 ◽  
Author(s):  
D. V. Ryzhkova ◽  
E. M. Nifontov ◽  
L. A. Tyutin
Keyword(s):  
Positron Emission Tomography ◽  
Blood Flow ◽  
Myocardial Blood Flow ◽  
Coronary Flow Reserve ◽  
Coronary Flow ◽  
Emission Tomography ◽  
Idiopathic Dilated Cardiomyopathy ◽  
Cardiovascular Pathology ◽  
Flow Reserve ◽  
Positron Emission

This article summarizes data of the studies with positron emission tomography (PET) and devotes the clinical application of PET for myocardial blood flow and coronary flow reserve measurement in the patients with cardiovascular pathology. Measurement of myocardial blood flow and coronary flow reserve allows to assess the functional importance of coronary stenosis in patients with coronary heart disease. According the results of experimental and clinical studies the impairment of coronary vasomotor reactivity seems to be the main cause of coronary microcirculatory abnormalities in the patients with high risk of cardiovascular diseases. Noninvasive PET diagnostics of myocardial blood flow provides the valuable information for stratification of the risk of the severe cardiovascular complications. PET seems to be a good tool for assessment of the medical treatment efficiency of arterial hypertension, diabetes mellitus, hypercholesterolemia and hypoestrogenemia. Myocardial blood flow impairment is independent prognostic marker of future adverse cardiac events and sudden cardiac death in patients with hypertrophic cardiomyopathy and idiopathic dilated cardiomyopathy.

scholarly journals Effect of long-term oral betablocker treatment on myocardial blood flow and coronary flow reserve in CAD-patients assessed with PET

2002 ◽  
Vol 39 ◽  
pp. 218
Author(s):  
Pascal Koepfli ◽  
Christophe A. Wyss ◽  
Anna-Katharina Kuenzle ◽  
Monika Hanggi ◽  
Thomas F. Luscher ◽  
...  
Keyword(s):  
Blood Flow ◽  
Myocardial Blood Flow ◽  
Coronary Flow Reserve ◽  
Coronary Flow ◽  
Flow Reserve

Persistent right coronary flow reserve at low perfusion pressure

1989 ◽  
Vol 256 (4) ◽  
pp. H1176-H1184 ◽  
Author(s):  
H. Murakami ◽  
S. J. Kim ◽  
H. F. Downey
Keyword(s):  
Blood Flow ◽  
Coronary Flow Reserve ◽  
Coronary Flow ◽  
Perfusion Pressure ◽  
Adenosine Infusion ◽  
Blood Flows ◽  
Flow Reserve ◽  
Anesthetized Dogs ◽  
Myocardial O2 Consumption ◽  
O2 Supply

To determine whether right coronary (RC) flow reserve persists at perfusion pressures below the apparent autoregulatory range, the RC artery of 18 anesthetized dogs was cannulated and perfused at controlled pressures. RC blood flow (RCBF) fell from 65.3 +/- 6.1 to 33.7 +/- 2.3 ml.min-1.100 g-1 as RC perfusion pressure (RCPP) was reduced from 80 to 40 mmHg. At 40 mmHg, intracoronary adenosine increased RCBF by 97.9 +/- 10.6 ml.min-1.100 g-1 (P less than 0.001). RCBF fell to 9.5 +/- 1.7 ml.min-1.100 g-1 at 20 mmHg, and RCBF did not significantly increase during adenosine, although RC vasodilation was observed in four dogs. Regional right ventricular (RV) blood flows at RCPP of 80 and 40 mmHg were measured by radioactive microsphere technique. Before adenosine infusion, RCBF was distributed uniformly across the RV free wall at normal and low perfusion pressures. During adenosine infusion, blood flow in both regions increased significantly, but the flow reserve was greater in the subendocardial region at both normal and reduced pressures. RV myocardial O2 consumption (MVo2) was decreased significantly at 40 mmHg, however, there was no evidence of ischemia at this pressure, since the RV lactate extraction ratio was normal (n = 8). Thus RV O2 demand fell when RC O2 supply was reduced, although a flow reserve was available. RV MVo2 was restored to normal when right coronary flow reserve was mobilized by adenosine infusion. For RCBF from 65 to 365 ml.min-1.100 g-1, RC venous O2 content rose and RV MVo2 was essentially constant.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Dynamic SPECT with assessment myocardial blood flow and coronary flow reserve in MINOCA patients: comparison with cardiac magnetic resonance

2021 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
A Mochula ◽  
OV Mochula ◽  
AN Maltseva ◽  
DA Vorobyeva ◽  
VV Ryabov ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Blood Flow ◽  
Cardiac Magnetic Resonance ◽  
Coronary Artery ◽  
Magnetic Resonance ◽  
Myocardial Perfusion ◽  
Myocardial Blood Flow ◽  
Coronary Flow Reserve ◽  
Coronary Flow ◽  
Flow Reserve

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): grant of the President of the Russian Federation Background. In recent years a group of patients with acute myocardial infarction without obstructive coronary artery disease (MINOCA) is of interest. In this group of patients, there is a lack of information related to myocardial perfusion, blood flow and reserve, which could be important in term of risk and prognosis assessment. Purpose. To assess the global and regional myocardial blood flow and coronary flow reserve impairment in MINOCA patients compared to cardiac magnetic resonance (CMR). Methods. The study group comprised 28 patients (18 male, mean 62.9 ± 10.7years) with acute coronary syndrome. Based on ICA results all patients were divided into two groups: 1) MINOCA (n = 11); 2) patients with myocardial infarction with obstructive CAD (MICAD) (n = 17). A total of 12/17 (71%) MICAD patients underwent PCI with stenting; in 2/12 cases two arteries were revascularized. Within 7-10 days after admission to the hospital all patients underwent SPECT myocardial perfusion scintigraphy (MPS) with the assessment of standard indices (SSS, SRS, SDS) and quantitative parameters: rest MBF (rMBF), stress MBF (sMBF) and CFR (on CZT gamma-camera). Also, all patients underwent CMR with evaluation of infarct size (IF), microvascular obstruction (MVO), size of myocardial edema (ME) and transmural extent of myocardial infarction (TE). Results Visual analysis showed that SSS differed significantly (p = 0.001) among MINOCA and MICAD groups: 5 (3;6) vs 10 (5;13), respectively. According to the quantitative MPS data analysis, global sMBF and CFR values were significantly higher in MINOCA than in MICAD patients group: 1.2 (0.82;1.69) ml/min/g vs 0.62 (0.52;0.9) ml/min/g; 1.96 (1.23;2.42) vs 1.16 (0.98;1.64) , respectively. CMR indices such as IS, ME and TE were significantly lower in MINOCA compared to MICAD patients: 1.6 (0;7.8) vs 14.8 (6.3;22.6)%; 8(0;14) vs 18.5 (10;23)%; 0 (0;5) vs 18 (10;25), respectively. Seven(40%) MICAD group patients showed MVO, whereas there were no such patients in MINIOCA group. The regional analysis revealed that sMBF and CFR were significantly lower in LV regions characterized by myocardial injury compared to non-injured regions (based on CMR data): 0.78 (0.51;0.94) ml/min/g vs 1.11 (0.82;1.4) and 1.22 (0.91;1.74) vs 1.52 (1.14;2.42), respectively. Also, we found out significant correlation between regional quantitative SPECT indices and transmural extent of myocardial infarction evaluated by CMR: r=–0.4 for sMBF; r=–0.35 for CFR (p &lt; 0.05). Conclusion. The analysis of quantitative MPS SPECT parameters showed that such approach allows identifying MBF and CFR disturbances both on global and regional level. These results showed that MINOCA patients characterized by mild reduction of myocardial blood flow and perfusion assessed visually and quantitatively. It means that despite the absence of obstructive coronary artery lesion this group of patients has more pronounced risk of cardiac events and need more aggressive observation and treatment.

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