Haemodynamic and energetic properties of stunned myocardium in rabbit hearts.

Schipke, Jochen D.; Korbmacher, B.; Dorszewski, A.; Sunderdiek, Ulrich; Arnold, G.

doi:10.1136/hrt.75.1.55

Cited by 10 publications

(4 citation statements)

References 50 publications

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“…In a model of stunning induced by demand ischemia, investigators found relaxation abnormalities but no change or only a slight increase in myocardial stiffness. 20,21 Complete functional recovery is expected, as indicated by the lack of necrotic tissue at histochemical staining. 22,23 Conversely, for transmurally infarcted myocardium, we found severely altered passive diastolic strain and SR during both early and late diastole, indicating abnormalities of both relaxation and compliance.…”

Section: Diastolic Strain and Sr Parametersmentioning

confidence: 99%

Ultrasound Strain Imaging of Altered Myocardial Stiffness

et al. 2004

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Background-In this study we evaluate the diastolic deformation of ischemic/reperfused myocardium and relate this deformation to tissue elastic properties. Methods and Results-Farm pigs were subjected to left anterior descending coronary artery occlusion followed by reperfusion to create either stunning (nϭ12) or transmural myocardial infarction (nϭ12). Ultrasound-derived radial strain rates (SR) and strain were measured in the ischemic and remote walls. Myocardial stiffness was estimated from diastolic pressure-wall thickness relationship obtained from preload alterations. At reperfusion, end-systolic strain (⑀ sys ) was significantly reduced in both stunned and infarcted walls compared with their remote walls (3Ϯ3% versus 26Ϯ2% and 1Ϯ0% versus 33Ϯ5%, respectively; PϽ0.0001) or baseline values. Diastolic passive deformation (⑀ A ) and rates of deformation during early (E SR ) and late (A SR ) diastole were comparable between stunned and remote walls (⑀ A : 7.3Ϯ1.6% versus 7.9Ϯ1.9%; E SR : Ϫ2.7Ϯ0.4 s Ϫ1 versus Ϫ2.6Ϯ0.5 s

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Section: Diastolic Strain and Sr Parametersmentioning

confidence: 99%

Ultrasound Strain Imaging of Altered Myocardial Stiffness

et al. 2004

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“…2 The formation of an infarct also alters physiological conditions, such as blood flow pattern, and hence the functionality of the myocardium surrounding the infarct. This dysfunctional tissue is further classified clinically into stunned [3][4][5] and hibernating 6,7 myocardium, based on its pathophysiological features.…”

Section: Introductionmentioning

confidence: 99%

In vivo characterization of myocardial infarction using fluorescence and diffuse reflectance spectroscopy

Chen

Lin

2010

J. Biomed. Opt.

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We explore the feasibility of using combined fluorescence and diffuse reflectance spectroscopy to characterize a myocardial infarct at different developing stages. An animal study is conducted using rats with surgically induced myocaridal infarction (MI). In vivo fluorescence spectra at 337-nm excitation and diffuse reflectance between 400 and 900 nm are measured from the heart. Spectral acquisition is performed: 1. for normal heart tissue; 2. for the area immediately surrounding the infarct; and 3. for the infarcted tissue itself, one, two, three, and four weeks into MI development. Histological and statistical analyses are used to identify unique pathohistological features and spectral alterations associated with the investigated regions. The main alterations (p<0.05) in diffuse reflectance spectra are identified primarily between 450 and 600 nm. The dominant fluorescence alterations are increases in peak fluorescence intensity at 400 and 460 nm. The extent of these spectral alterations is related to the duration of the infarction. The findings of this study support the concept that optical spectroscopy could be useful as a tool to noninvasively determine the in vivo pathophysiological features of a myocardial infarct and its surrounding tissue, thereby providing real-time feedback to surgeons during various surgical interventions for MI.

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“…Instead, a ''metabolic stunning'' occurs at the level of both excitation-contraction coupling and force development by the contractile apparatus. myocardial stunning; isolated heart; rabbit DESPITE THE ABUNDANCE of literature on myocardial stunning (2,10,24,27), the phenomenon remains poorly understood. Although ventricular function is substantially depressed, O 2 consumption (V O 2 ) in the stunned myocardium is normal or close to normal (1,16,18).…”

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confidence: 99%

Basal metabolism does not account for high O₂consumption in stunned myocardium

Schipke

Korbmacher

Schwanke³

et al. 1998

American Journal of Physiology-Heart and Circulatory Physiology

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Myocardial O2 consumption (MV˙o 2) in stunned myocardium is relatively high compared with the reduced ventricular function. The mechanism of this “oxygen paradox” could occur at different levels: basal metabolism, excitation-contraction coupling, and energy production. In one previously reported series on 12 isolated, blood-perfused rabbit hearts, left ventricular systolic and diastolic function in stunned myocardium were significantly decreased compared with control, whereas total MV˙o 2 was not. The MV˙o 2 for the unloaded contraction was overproportionately high for the decreased function in stunned myocardium, and contractile efficiency was clearly deteriorated. To assess whether the basal metabolism specifically is elevated in stunned myocardium, a second series ( n =14) with a similar protocol was performed in this study. Basal MV˙o 2 after KCl arrest (0.5 ± 0.3 ml ⋅ min−1 ⋅ 100 g−1) was significantly lower than that measured after KCl arrest (1.2 ± 0.5 ml ⋅ min−1 ⋅ 100 g−1) in an additional series on nonischemic hearts ( n = 8). Our conclusion is that basal MV˙o 2 in stunned myocardium is not elevated. Thus this O2-consuming portion of total MV˙o 2 is not responsible for the inefficiency in stunned myocardium. Instead, a “metabolic stunning” occurs at the level of both excitation-contraction coupling and force development by the contractile apparatus.

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Haemodynamic and energetic properties of stunned myocardium in rabbit hearts.

Cited by 10 publications

References 50 publications

Ultrasound Strain Imaging of Altered Myocardial Stiffness

Ultrasound Strain Imaging of Altered Myocardial Stiffness

In vivo characterization of myocardial infarction using fluorescence and diffuse reflectance spectroscopy

Basal metabolism does not account for high O₂consumption in stunned myocardium

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Haemodynamic and energetic properties of stunned myocardium in rabbit hearts.

Cited by 10 publications

References 50 publications

Ultrasound Strain Imaging of Altered Myocardial Stiffness

Ultrasound Strain Imaging of Altered Myocardial Stiffness

In vivo characterization of myocardial infarction using fluorescence and diffuse reflectance spectroscopy

Basal metabolism does not account for high O2consumption in stunned myocardium

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Basal metabolism does not account for high O₂consumption in stunned myocardium