Compensatory changes of the distal coronary vascular bed during progressive coronary constriction.

Gould, K. Lance; Lipscomb, Kirk; Calvert, Clay A.

doi:10.1161/01.cir.51.6.1085

Cited by 234 publications

(73 citation statements)

References 24 publications

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“…(It should be emphasized that the pressure axis intercepts and peripheral coronary pressures should be similar, as shown in Figure 3, because the pressure during complete coronary occlusion is indeed the lowest point on the pressure-flow curve.) In the isolated circumflex coronary artery, pressures of 14-30 mm Hg have been reported for peripheral coronary pressures (Mosher et al, 1964;Fam and McGregor, 1964;Elliot et al, 1968;Fam and McGregor, 1969;Elliot et al, 1974;Gould et al, 1975) and for pressure axis intercepts (Bellamy, 1978;Verrier et al, 1980;Vlahakes et al, 1982;Dole and Bishop, 1982). On the other hand, in the left main coronary artery, Eng et al (1982) found an average pressure axis intercept of 10.7 ± 2.4 mm Hg, close to our mean value of 8.1 mm Hg; had they used curvilinear rather than linear extrapolation, their intercept would have been even lower.…”

Section: Effects Of Interarterial Pressure Gradientssupporting

confidence: 81%

Effects of pressure gradients between branches of the left coronary artery on the pressure axis intercept and the shape of steady state circumflex pressure-flow relations in dogs.

Messina¹,

Hanley²,

Uhlig³

et al. 1985

Circulation Research

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SUMMARY. When steady state pressure-flow relations are studied in the circumflex coronary artery, pressure gradients develop between it and other branches of the left coronary artery. To assess the effects of these pressure gradients, we compared the pressure axis intercept and shape of steady state circumflex pressure-flow relations in the presence and absence of gradients after autoregulation was abolished, both in the beating heart and during long diastoles in dogs. We used peripheral coronary pressures and radionuclide-labeled microspheres to assess arterial collateral flow. In the beating heart, interarterial pressure gradients reduced the curvature at low circumflex pressures, and overestimated the mean pressure axis intercept by 7.8 mm Hg (P < 0.05). The results were similar for the pressure-flow relations derived during long diastoles. This overesrimation exaggerates the difference between the pressure axis intercept and coronary sinus pressure. The peripheral coronary pressure and microsphere results indicate that these effects are mediated largely by arterial collateral flow. {Circ Res 56: 11-19, 1985) CORONARY arterial pressure-flow relations have been used to investigate the physical forces that regulate coronary blood flow (Cross et al., 1961;Downey and Kirk, 1975;Bellamy, 1978). The pressure axis intercept of these relations has been interpreted as the downstream pressure opposing forward flow in the coronary circulation; however, this pressure has greatly exceeded the coronary sinus pressure, which traditionally has been assumed to be the downstream pressure. The shape of these relations, found to be linear by some (Dole and Bishop, 1982;Eng et al., 1982) but curvilinear by others (L'Abbate et al., 1980;Klocke et al., 1981), is thought to convey information about the conductance of the coronary circulation. Because of this variability of the pressure axis intercept and the shape of coronary arterial pressure-flow relations, the physiological significance of both remains uncertain.One factor that might account for this variability is the specific coronary artery in which the pressureflow relation is obtained. In our laboratory, we have consistently found that the pressure axis intercept of a steady state circumflex pressure-flow relation (Verrier et al., 1980;Vlahakes et al., 1982) is much higher than that in a steady state left main coronary arterial pressure-flow relation (Rouleau et al., 1979;Uhlig et al., 1984). A possible explanation for the higher pressure axis intercept of the circumflex pressure-flow relation may be that when circumflex pressure is selectively lowered below that in the other branches of the left coronary artery, interarterial pressure gradients occur and are accompanied by collateral flow that is not measured by the upstream flow transducer. This error in measurement could underestimate total circumflex flow and thus overestimate the pressure axis intercept. Whether these pressure gradients also affect the shape of a circumflex pressure-flow relation is unknown.To assess...

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Section: Effects Of Interarterial Pressure Gradientssupporting

confidence: 81%

Effects of pressure gradients between branches of the left coronary artery on the pressure axis intercept and the shape of steady state circumflex pressure-flow relations in dogs.

Messina¹,

Hanley²,

Uhlig³

et al. 1985

Circulation Research

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show abstract

“…Such findings may agree with the Hagen-Poiseuille law, which denotes the resistance to flow in a tube interacting with serial branches along its length. 27 According to this, the intracoronary resistance depends on the coronary flow velocity and inversely on the fourth power of the vessel diameter, while interacting with branches along its length, that causes flow shunting from the parent artery and the longitudinal perfusion or MBF gradient. As it was observed, the extent of the longitudinal MBF difference was related to the severity of CAC, which has been shown to reflect overall CAD burden, 26 and also to the increase in hyperemic MBF or microvascular function.…”

Section: Discussionmentioning

confidence: 99%

Structural epicardial disease and microvascular function are determinants of an abnormal longitudinal myocardial blood flow difference in cardiovascular risk individuals as determined with PET/CT

Valenta

Quercioli

Vincenti

et al. 2010

Journal of Nuclear Cardiology

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Background. The aim of this study was to determine whether epicardial structural disease may affect the manifestation of a longitudinal decrease in myocardial blood flow (MBF) or MBF difference during hyperemia in cardiovascular risk individuals, and its dependency on the flow increase.Methods and Results. In 54 cardiovascular risk individuals (at risk) and in 26 healthy controls, MBF was measured with 13 N-ammonia and PET/CT in mL/g/min at rest and during dipyridamole stimulation. Computed tomography coronary angiography (CTA) was performed using a 64-slice CT of a PET/CT system. Absolute MBFs during dipyridamole stimulation were mildly lower in the mid-distal than in the mid-LV myocardium in controls (2.20 ± .51 vs 2.29 ± .51, P < .0001), while it was more pronounced in at risk with normal and abnormal CTA (1.56 ± .42 vs 1.91 ± .46 and 1.18 ± .34 vs 1.51 ± .40 mL/g/min, respectively, P < .0001), resulting in a longitudinal MBF difference that was highest in at risk with normal CTA, intermediate in at risk abnormal CTA, and lowest in controls (.35 ± .16 and .22 ± .09 vs .09 ± .04 mL/g/min, respectively, P < .0001). On multivariate analysis, log-CCS and mid-LV hyperemic MBF increase, indicative of microvascular function, were independent predictors of the observed longitudinal MBF difference (P £ .004 by ANOVA).Conclusions. Epicardial structural disease and microvascular function are important determinants of an abnormal longitudinal MBF difference as determined with PET/CT. (J Nucl Cardiol 2010;17:1023-33.)

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“…Group 1 patients (14 men, one woman; age, 55±7 years; range, years) were selected for the study because of the following characteristics: 1) isolated, proximal left anterior descending coronary artery stenosis, 2) stable angina pectoris associated with objective signs of myocardial ischemia on effort or during dipyridamole echocardiography test, 3) no clinical or ECG evidence of previous myocardial infarction, 4) no history of hypertension or left ventricular hypertrophy (septal or posterior wall < 12 mm at echocardiography), 5) no conduction abnormalities, and 6) exclusion of other cardiac disorders.…”

Section: Methods Patientsmentioning

confidence: 99%

Residual coronary reserve despite decreased resting blood flow in patients with critical coronary lesions. A study by technetium-99m human albumin microsphere myocardial scintigraphy.

et al. 1993

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Background. Experimental data demonstrate the persistence of a transmural vasodilator reserve in the face of depressed resting myocardial perfusion. The present study was designed to determine whether resting myocardial hypoperfusion indicates exhausted coronary reserve (CR).Methods and Results. Fifteen patients with stable angina, isolated left anterior descending coronary artery (LAD) stenosis, and no previous myocardial infarction were evaluated by means of "'Tc human albumin microsphere scintigraphy. Regional myocardial perfusion and CR were assessed at baseline and after LAD papaverine (10-12 mg) by means of two microsphere injections in the left ventricle and compared with five normal subjects. Two 300-second scans were obtained with a mobile gamma camera positioned in the 700 left anterior oblique projection; actual microsphere distribution after papaverine was obtained by image subtraction. The two arterial input functions (basal and papaverine) were measured

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Compensatory changes of the distal coronary vascular bed during progressive coronary constriction.

Cited by 234 publications

References 24 publications

Effects of pressure gradients between branches of the left coronary artery on the pressure axis intercept and the shape of steady state circumflex pressure-flow relations in dogs.

Effects of pressure gradients between branches of the left coronary artery on the pressure axis intercept and the shape of steady state circumflex pressure-flow relations in dogs.

Structural epicardial disease and microvascular function are determinants of an abnormal longitudinal myocardial blood flow difference in cardiovascular risk individuals as determined with PET/CT

Residual coronary reserve despite decreased resting blood flow in patients with critical coronary lesions. A study by technetium-99m human albumin microsphere myocardial scintigraphy.

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