Quantification of myocardial perfusion and determination of coronary stenosis severity during hyperemia using real-time myocardial contrast echocardiography

Leong‐Poi, Howard; Le, Elizabeth; Rim, Se Joong; Sakuma, Tadamichi; Kaul, Sanjiv; Wei, Kevin

doi:10.1067/mje.2001.115982

Cited by 82 publications

(61 citation statements)

References 6 publications

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“…Although our visual analysis of MCR focused mainly on frames obtained near end systole, a triggered technique that captures images only at end systole may assist in preventing interference from large intramyocardial arterioles, which have been shown to worsen the corre- lation between MCR and myocardial blood flow changes. 36 In addition, quantitative analyses of MCR have been shown to be feasible during vasodilator stress and may improve the detection of stenoses in a particular CAT. 37 Twenty-nine percent of patients in the present study had prior myocardial infarction.…”

Section: Study Limitationsmentioning

confidence: 99%

Rapid Detection of Coronary Artery Stenoses With Real-Time Perfusion Echocardiography During Regadenoson Stress

Porter

Adolphson

High

et al. 2011

Circ: Cardiovascular Imaging

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Background-Real-time myocardial contrast echocardiography permits the detection of myocardial perfusion abnormalities during stress echocardiography, which may improve the accuracy of the test in detecting coronary artery stenoses. We hypothesized that this technique could be used after a bolus injection of the selective A2A receptor agonist regadenoson to rapidly and safely detect coronary artery stenoses. Methods and Results-In 100 patients referred for quantitative coronary angiography, real-time myocardial contrast echocardiography was performed during a continuous intravenous infusion of 3% Definity at baseline and at 2-minute intervals for up to 6 minutes after a regadenoson bolus injection (400 g). Myocardial perfusion was assessed by examination of myocardial contrast replenishment after brief high mechanical index impulses. A perfusion defect was defined as a delay (Ͼ2 seconds) in myocardial contrast replenishment in 2 contiguous segments. Wall motion was also analyzed. The overall sensitivity/specificity/accuracy for myocardial perfusion analysis in detecting a Ͼ50% diameter stenosis was 80%/74%/78%, whereas for wall motion analysis it was 60%/72%/66% (PϽ0.001 for differences in sensitivity). Sensitivity for myocardial perfusion analysis was highest on images obtained during the first 2 minutes after regadenoson bolus (PϽ0.001 compared with wall motion), whereas wall motion sensitivity was highest at the 4-to-6 -minute period after the bolus. No significant side effects occurred after regadenoson bolus injection. Conclusions-Regadenoson

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Section: Study Limitationsmentioning

confidence: 99%

Rapid Detection of Coronary Artery Stenoses With Real-Time Perfusion Echocardiography During Regadenoson Stress

Porter

Adolphson

High

et al. 2011

Circ: Cardiovascular Imaging

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“…When sonified with ultrasound in their resonance frequency (between 1 and 2 MHz), high mechanical index ultrasound will induce high amplitude oscillations that lead to microbubble destruction. Although this phenomenon can be used to characterize refill kinetics of tissue perfusion, 29 it can also be used to deliver a microbubble-loaded bioactive substance into an organ. 30,31 In addition, UTMD benefits from secondary effects of microbubble destruction that will increase capillary permeability and produce transient nanopores in cell membranes by developing high velocity fluid microjets in their near vicinity.…”

Section: Introductionmentioning

confidence: 99%

Augmentation of AAV-mediated cardiac gene transfer after systemic administration in adult rats

et al. 2008

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“…When destructive pulses are used to obtain replenishment curves during low-MI imaging, the signals in the initial portion of the curve arise from arterioles 23 that fill faster, and those in the plateau portion arise mostly from capillaries. However, even in this instance, phasic changes in VI may be related to changes in microbubble size, the small degree of microbubble destruction, or tissue motion artifact and do not reflect any physiological phenomena.…”

Section: Discussionmentioning

confidence: 99%

Detection of Noncritical Coronary Stenosis at Rest Without Recourse to Exercise or Pharmacological Stress

Wei

Jayaweera

et al. 2002

Circulation

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Background-Currently, the detection of noncritical coronary stenoses requires some form of stress. We hypothesized that these stenoses can be detected at rest without recourse to stress by assessing adaptive changes that occur distally in the microcirculation. Methods and Results-Phasic changes in myocardial video intensity (VI) were measured at rest with continuous high-mechanical-index (MI) contrast echocardiography in 15 open-chest dogs. Data were acquired at baseline and in the presence of different degrees of noncritical coronary stenosis. In 6 of these dogs, capillary blood volume was also measured at baseline using high-MI intermittent imaging with triggering performed separately at both end diastole and end systole. During continuous high-MI imaging, a significant increase in systolic VI was noted with coronary stenoses that resulted in progressive increases in the systolic/diastolic VI ratio with greater degrees of stenosis (Pϭ0.003), with a mildly quadratic relation noted between the two: yϭ1.3 · 10 Ϫ6 · x 2 ϩ0.01xϩ0.32, PϽ0.001, rϭ0.76, SEEϭ0.14. There was no difference in capillary blood volume between end diastole and end systole at baseline. Conclusions-Capillary blood volume does not change between diastole and systole in vivo. Phasic changes in VI are noted at baseline during high-MI continuous imaging. The systolic component is negligible at baseline but increases with increasing levels of noncritical coronary stenosis because of adaptive changes in the microcirculation distal to the stenosis. Thus, the measurement of phasic changes in myocardial VI has the potential to detect coronary stenosis at rest without recourse to any form of stress. Key Words: stenosis Ⅲ echocardiography Ⅲ blood volume B ecause of autoregulation, coronary blood flow (CBF) remains normal at rest until a coronary stenosis exceeds Ϸ85% in severity. 1,2 In the absence of a prior infarction, therefore, noncritical coronary stenoses cannot be detected by cardiac imaging at rest, and some form of stress is required to induce either regional dysfunction or a perfusion abnormality. The same is true even for electrocardiography.When coronary arterioles dilate in the presence of a noncritical stenosis, their blood volume (aBV) increases. 3,4 A portion of these arterioles are intramyocardial. 5 We hypothesized that because the degree of dilation of the coronary arterioles is related to the severity of stenosis, 3,4,6 aBV should increase in proportion to coronary stenosis severity. If this phenomenon could be measured noninvasively, the presence and severity of noncritical coronary stenosis could be measured at rest without recourse to any form of stress.Whereas phasic changes in intramyocardial arteriolar dimensions have been documented during cardiac contraction, 7 there is controversy regarding changes in capillary dimensions during this period. 8 -11 We postulated that because arterioles and venules are larger than capillaries, their compression would occur early in systole, causing an increase in their resistance that would re...

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Quantification of myocardial perfusion and determination of coronary stenosis severity during hyperemia using real-time myocardial contrast echocardiography

Cited by 82 publications

References 6 publications

Rapid Detection of Coronary Artery Stenoses With Real-Time Perfusion Echocardiography During Regadenoson Stress

Rapid Detection of Coronary Artery Stenoses With Real-Time Perfusion Echocardiography During Regadenoson Stress

Augmentation of AAV-mediated cardiac gene transfer after systemic administration in adult rats

Detection of Noncritical Coronary Stenosis at Rest Without Recourse to Exercise or Pharmacological Stress

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