Transmural coronary flow reserve patterns in dogs

Grattan, Mark T.; Hanley, Frank L.; Stevens, M. B.; Hoffman, Julien I.E.

doi:10.1152/ajpheart.1986.250.2.h276

Cited by 26 publications

(16 citation statements)

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“…The numbers of microspheres per 1µL of heart tissue were determined in each region. The mean±SEM ratio of endocardial to epicardial microspheres is 1.33±0.11 (n=11), consistent with observations in dogs [23][24][25] and humans. 26 The serially and simultaneously injected hearts were also virtually dissected into endocardial and epicardial regions, and the numbers of microspheres per 1µL of heart tissue were determined in each region.…”

Section: Mouse Heart Experimentssupporting

confidence: 88%

Visualizing Regional Myocardial Blood Flow in the Mouse

Krueger

Huke

Glenny

2013

Circulation Research

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Rationale:The spatial distribution of blood flow in the hearts of genetically modified mice is a phenotype of interest because derangements in blood flow may precede detectable changes in organ function. However, quantifying the regional distribution of blood flow within organs of mice is challenging because of the small organ volume and the high resolution required to observe spatial differences in flow. Traditional microsphere methods in which the numbers of microspheres per region are indirectly estimated from radioactive counts or extracted fluorescence have been limited to larger organs for 2 reasons; to ensure statistical confidence in the measured flow per region and to be able to physically dissect the organ to acquire spatial information.

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Section: Mouse Heart Experimentssupporting

confidence: 88%

Visualizing Regional Myocardial Blood Flow in the Mouse

Krueger

Huke

Glenny

2013

Circulation Research

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“…Thus, coronary hypotension reduces more rapidly coronary reserve in left ventricular subendocardium, 5 although a pharmacologically demonstrable reserve remains at coronary pressures as low as 30 mm Hg. 9 In the present study, we found that the transmural distribution of flow across the right ventricular wall was not altered by right coronary hypotension. This finding is consistent with differences in the left and right coronary artery phasic flow patterns.…”

Section: Discussionsupporting

confidence: 52%

Transmural variation in autoregulation of right ventricular blood flow.

Yonekura

Watanabe

Downey

1988

Circulation Research

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We examined transmurally the right coronary autoregulatory flow response to varied perfusion pressures in 11 anesthetized, open-chest dogs. Right coronary artery flow was measured electromagneticalry, and its transmural distribution was denned with 15-(im radioactive microspheres. Heart rate, mean aortic blood pressure, right ventricular systolic pressure, end-diastolic pressure, and dP/dt_ were constant. At 100 mm Hg, subepicardial flow averaged 0.48 ±0.04 ml/min/g, and subendocardial flow averaged 0.56 ± 0.05 ml/min/g. In contrast to the left coronary circulation, right coronary hypotension did not cause preferential subendocardial ischemia. As right coronary perfusion pressure was decreased from 100 to 40 mm Hg in five dogs, subepicardial and subendocardial flows were reduced similarly by 35-36%. As right coronary perfusion pressure was elevated from 100 to 150 mm Hg in six dogs, right ventricular subepicardial blood flow increased by 31%, whereas 5 a phenomenon known as autoregulation.6 When left coronary perfusion pressure is decreased below the autoregulatory pressure range, regional flow falls more precipitously in subendocardium, 7 "9 and the subendocardial-to-subepicardial flow ratio (endo/epi) reaches approximately 0.3 at complete occlusion of the left coronary artery.8 When left coronary perfusion pressure is increased above the autoregulatory pressure range, the endo/epi ratio increases, 10 indicating that left coronary autoregulation fails first in subendocardium. To date, there have been no reports of regional autoregulatory capability in the right coronary circulation, although we recently found that right coronary artery autoregulation was less potent than left coronary autoregulation." It is possible that the blunted autoregulatory capability of the right coronary circulation has a regional basis like that of the blunted capability Received June 8, 1987; accepted November 2, 1987. of the hyperperfused left coronary circulation. 10 Thus, this investigation was conducted to define transmurally right coronary autoregulatory capability over a wide range of right coronary perfusion pressures. Materials and MethodsEleven mongrel dogs of either sex, weighing 15 to 24 kg, were anesthetized with sodium pentobarbital, 30 mg/kg i.v. initially, and supplemented as needed to maintain stable anesthesia. After tracheotomy, the dogs were ventilated by a respirator (Harvard Apparatus, South Natick, Massachusetts) with room air supplemented with oxygen to maintain normal arterial oxygen tension. A vinyl catheter was positioned in the inferior vena cava through a femoral vein for administration of supplementary anesthetic, heparin, and fluids. A second vinyl catheter was advanced into the thoracic aorta through a femoral artery to monitor aortic pressure. Right ventricular pressure was measured with a catheter-tipped transducer (Millar Instruments, Houston, Texas) inserted through the right jugular vein and across the tricuspid valve. The right ventricular pressure signal was differentiated electronically, and ...

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“…As a result, the transmural myocardial vulnerability to a reduction in coronary artery flow is also heterogeneous. When coronary blood flow decreases, the subendocardium is affected earlier and to a greater degree than the subepicardium [3,4,5], leading to an increased transmural gradient of myocardial perfusion. Therefore, measurement of this transmural gradient plays an important role in the early detection and intervention of myocardial ischemia and has been the goal pursued by many novel imaging techniques.…”

Section: Introductionmentioning

confidence: 99%

Transmural Peak Systolic Strain and Strain Rate Predict Transmural Myocardial Blood Flow in a Pig Myocardial Infarction Model

Yao

Lin

et al. 2008

Cardiology

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Objective: To test the hypothesis that the transmural variation of the longitudinal myocardial peak systolic strain (Sp) and strain rate (SRp) can predict the transmural distribution of myocardial blood flow (MBF) in a pig model of acute myocardial infarction. Methods: The longitudinal Sp and SRp were measured by echocardiography in both subendocardium (Sp-endo, SRp-endo) and subepicardium (Sp-epi, SRp-epi) in the normal, ischemic and infarct segments, respectively. The MBF in corresponding sites was measured by colored microspheres technique. The subendocardial to subepicardial ratio of Sp (Sp-EER), SRp (SRp-EER) and MBF (MBF-EER) were calculated. Results: In the normal segments, Sp-endo and SRp-endo were significantly higher than Sp-epi and SRp-ep, respectively. In the ischemic segments, Sp-endo and SRp-endo decreased to a greater extent than Sp-epi and SRp-epi, respectively. In the infarct segments, Sp-endo, SRp-endo Sp-epi and SRp-epi were all remarkably reduced. High correlations were found between Sp and SRp measurements and MBF in both subendocardium and subepicardium (r = –0.75 to –0.84, p < 0.001). Conclusion: Strain and strain rate imaging provides a reliable approach to the noninvasive estimation of the transmural blood distribution across the normal, ischemic and infarct segments.

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Transmural coronary flow reserve patterns in dogs

Cited by 26 publications

References 0 publications

Visualizing Regional Myocardial Blood Flow in the Mouse

Visualizing Regional Myocardial Blood Flow in the Mouse

Transmural variation in autoregulation of right ventricular blood flow.

Transmural Peak Systolic Strain and Strain Rate Predict Transmural Myocardial Blood Flow in a Pig Myocardial Infarction Model

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