Myocardial oxygenation in dogs during partial and complete coronary artery occlusion.

Parsons, William J.; Rembert, Judith C.; Bauman, Robert P.; Duhaylongsod, Francis G.; Greenfield, Joseph C.; Piantadosi, CA

doi:10.1161/01.res.73.3.458

Cited by 30 publications

(40 citation statements)

References 28 publications

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“…The underlying physiology of myocardial ischemia, however, goes along with a parallel drop of blood flow, volume, and tissue oxygenation. 15 Thus, from a clinical point of view, the multifactorial pattern of the SI change does not affect the conclusion.…”

Section: Discussionmentioning

confidence: 94%

Blood oxygen level-dependent magnetic resonance imaging in patients with stress-induced angina

Friedrich¹,

Niendorf²,

Schulz‐Menger³

2004

ACC Current Journal Review

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Background-Blood oxygen level-dependent (BOLD) MRI reflects tissue oxygenation and may be useful for the detection of myocardial ischemia in patients with suspected coronary artery disease. Methods and Results-We studied 25 patients with stress-induced angina using a T 2 *-sensitive echo planar imaging sequence before and during adenosine in a single-slice approach. BOLD-MRI results were compared with quantitative angiography and adenosine thallium single-photon emission computed tomography (SPECT). Although image quality was variable because of artifacts, no data were excluded from the analysis. During adenosine, a mean signal intensity decrease was observed for myocardial segments related to coronary stenoses Ͼ75%. On average, a nonsignificant increase was observed in the other segments. The angiographically determined stenosis was correlated with BOLD-MRI results. Including all segments and using BOLD-MRI signal intensity increase cutoff value of 1.2%, BOLD-MRI had a sensitivity of 88% and a specificity of 47% to correctly classify severe stenoses. Adenosine thallium SPECT data from distal segments of the same coronary territory were also correlated with BOLD-MRI. However, variability was substantial. Conclusions-In patients with stress-induced angina, adenosine BOLD-MRI detects myocardial ischemia in myocardial segments related to severe coronary stenoses. Its potential will increase with additional improvement of spatial coverage and image quality.

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Section: Discussionmentioning

confidence: 94%

Blood oxygen level-dependent magnetic resonance imaging in patients with stress-induced angina

Friedrich¹,

Niendorf²,

Schulz‐Menger³

2004

ACC Current Journal Review

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“…The reproducibility of changes in optical density to a given intervention in a given subject was determined in preliminary studies where handgrip at 45% maximal voluntary contraction (MVC), lower body negative pressure (LBNP) at Ϫ 20 mmHg, and forearm circulatory arrest (to obtain the TLS) was performed twice on four subjects. The differences (mean Ϯ SD) in the change in optical density between the two tests were (cyt a,a 3 The near infrared spectrophotometer, which was constructed in Dr. Claude Piantadosi's laboratory (53)(54)(55), consists of four GaAIAs laser diodes and circuitry for photodetection, demodulation, and logarithmic amplification of the optical signals. The four lasers in sequence provide pulses of monochromatic light (1.5-nm bandwidth) at 775, 810, 870, and 904 nm.…”

Section: In Vivo Near Infrared Multiwavelength Spectroscopymentioning

confidence: 99%

“…Near infrared spectroscopy has been validated extensively (48)(49)(50)(59)(60)(61) and the algorithms used to separate cyt a,a 3 , tHbO 2 ϩ MbO 2 , and tHb ϩ Mb signals have been published (54,55,60). The validity of these algorithms has been established in experimental animal models using exchange transfusions with perfluorocarbon blood substitutes (60).…”

Section: In Vivo Near Infrared Multiwavelength Spectroscopymentioning

confidence: 99%

Differential sympathetic neural control of oxygenation in resting and exercising human skeletal muscle.

Hansen¹,

Thomas²,

Harris³

et al. 1996

J. Clin. Invest.

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117

174

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Metabolic products of skeletal muscle contraction activate metaboreceptor muscle afferents that reflexively increase sympathetic nerve activity (SNA) targeted to both resting and exercising skeletal muscle. To determine effects of the increased sympathetic vasoconstrictor drive on muscle oxygenation, we measured changes in tissue oxygen stores and mitochondrial cytochrome a,a 3 redox state in rhythmically contracting human forearm muscles with near infrared spectroscopy while simultaneously measuring muscle SNA with microelectrodes. The major new finding is that the ability of reflex-sympathetic activation to decrease muscle oxygenation is abolished when the muscle is exercised at an intensity Ͼ 10% of maximal voluntary contraction (MVC). During high intensity handgrip (45% MVC), contractioninduced decreases in muscle oxygenation remained stable despite progressive metaboreceptor-mediated reflex increases in SNA. During mild to moderate handgrips (20-33% MVC) that do not evoke reflex-sympathetic activation, experimentally induced increases in muscle SNA had no effect on oxygenation in exercising muscles but produced robust decreases in oxygenation in resting muscles. The latter decreases were evident even during maximal metabolic vasodilation accompanying reactive hyperemia.We conclude that in humans sympathetic neural control of skeletal muscle oxygenation is sensitive to modulation by metabolic events in the contracting muscles. These events are different from those involved in either metaboreceptor muscle afferent activation or reactive hyperemia. ( J. Clin. Invest. 1996. 98:584-596.)

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“…The good penetration of the NIR light into soft tissue makes the NIR spectroscopy appropriate for invivo detection of blood and/or tissue bound oxygendependent chromophores such as hemoglobin, myoglobin and cytochromes. 7 For spectroscopic analysis of tissue under in-vivo-conditions, specific light diodes (optodes) are required which usually work in a dual configuration with emitting and collecting light transmitted through the tissue sample. 8 Collected NIR light is transferred by a fiberoptic cable to a photomultiplier and converted into an electric signal.…”

Section: Nir Spectroscopymentioning

confidence: 99%

I.V. NIRS off-pump coronary artery ischemia monitoring bypass surgery

Tekalkote

Hussein

2018

Int Surg J

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INTRODUCTIONNear-infrared (NIR) spectroscopy is an appropriate method for ischemia monitoring in myocardial tissue. 1 An acute deterioration of coronary blood supply can result in a release of ischemic metabolites, predominantly oxygen-dependent chromophores into the coronary sinus. These metabolites are detectable in the coronary sinus blood, often prior to the appearance of substances representing cellular injury such as troponins and creatine kinase (CK-MB) in the peripheral blood. The online intravascular NIR spectroscopic analysis of the coronary sinus blood with a fiberoptic catheter allows a direct ischemia monitoring at myocardial level. 2 The aim of present study was to evaluate the clinical reliability of myocardial ischemia monitoring by using intravascular NIR spectroscopy in OPCAB surgery. The intraoperative management of hemodynamic changes in off-pump ABSTRACT Background: Spectroscopic data were compared with hemodynamic parameters, electrocardiogram, transesophageal echocardiography and laboratory findings. A conversion to extracorporeal circulation was not necessary. The mean number of grafts per patient was 3.1±0.6. An intraoperative myocardial ischemia was not evident, as indicated by electrocardiogram and transesophageal echocardiography. Methods: Continuous spectroscopic analysis showed reproducible absorption spectra of coronary sinus blood. Due to uneventful intraoperative courses, clear ischemia-related changes could be detected in none of the patients. Present initial results show that intravascular near-infrared spectroscopy can reliably be used for an online intraoperative ischemia monitoring in off-pump coronary artery bypass surgery. Results: In 15 elective patients undergoing off-pump myocardial revascularization, intravascular near-infrared spectroscopic analysis of coronary venous blood was performed. NIR signals were transferred through a fiberoptic catheter for signal emission and collection. For data analysis and processing, a miniature spectrophotometer with multivariate statistical package was used. Signal acquisition and analysis were performed before and after revascularization. However, the method has to be further evaluated and standardized to determine the role of spectroscopy in off-pump coronary artery bypass surgery. In off-pump coronary artery bypass surgery, manipulations on the beating heart can lead to transient interruptions of myocardial oxygen supply, which can generate an accumulation of oxygen-dependent metabolites in coronary venous blood. Conclusions: The objective of this study was to evaluate the reliability of intravascular near-infrared spectroscopy as a monitoring method to detect possible ischemic events in off-pump coronary artery bypass procedures.

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Myocardial oxygenation in dogs during partial and complete coronary artery occlusion.

Abstract: Regional myocardial oxygenation was assessed during partial and complete coronary artery occlusion using near

Cited by 30 publications

References 28 publications

Blood oxygen level-dependent magnetic resonance imaging in patients with stress-induced angina

Blood oxygen level-dependent magnetic resonance imaging in patients with stress-induced angina

Differential sympathetic neural control of oxygenation in resting and exercising human skeletal muscle.

I.V. NIRS off-pump coronary artery ischemia monitoring bypass surgery

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