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Lindsey ML, Bolli R, Canty JM, Du XJ, Frangogiannis NG, Frantz S, Gourdie RG, Holmes JW, Jones SP, Kloner RA, Lefer DJ, Liao R, Murphy E, Ping P, Przyklenk K, Recchia FA, Schwartz Longacre L, Ripplinger CM, Van Eyk JE, Heusch G. Guidelines for experimental models of myocardial ischemia and infarction. Am J Physiol Heart Circ Physiol 2018; 314:H812-H838. [PMID: 29351451 PMCID: PMC5966768 DOI: 10.1152/ajpheart.00335.2017] [Citation(s) in RCA: 338] [Impact Index Per Article: 56.3] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Myocardial infarction is a prevalent major cardiovascular event that arises from myocardial ischemia with or without reperfusion, and basic and translational research is needed to better understand its underlying mechanisms and consequences for cardiac structure and function. Ischemia underlies a broad range of clinical scenarios ranging from angina to hibernation to permanent occlusion, and while reperfusion is mandatory for salvage from ischemic injury, reperfusion also inflicts injury on its own. In this consensus statement, we present recommendations for animal models of myocardial ischemia and infarction. With increasing awareness of the need for rigor and reproducibility in designing and performing scientific research to ensure validation of results, the goal of this review is to provide best practice information regarding myocardial ischemia-reperfusion and infarction models. Listen to this article’s corresponding podcast at ajpheart.podbean.com/e/guidelines-for-experimental-models-of-myocardial-ischemia-and-infarction/.
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Affiliation(s)
- Merry L Lindsey
- Mississippi Center for Heart Research, Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, Mississippi.,Research Service, G. V. (Sonny) Montgomery Veterans Affairs Medical Center , Jackson, Mississippi
| | - Roberto Bolli
- Division of Cardiovascular Medicine and Institute of Molecular Cardiology, University of Louisville , Louisville, Kentucky
| | - John M Canty
- Division of Cardiovascular Medicine, Departments of Biomedical Engineering and Physiology and Biophysics, The Veterans Affairs Western New York Health Care System and Clinical and Translational Science Institute, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo , Buffalo, New York
| | - Xiao-Jun Du
- Baker Heart and Diabetes Institute , Melbourne, Victoria , Australia
| | - Nikolaos G Frangogiannis
- The Wilf Family Cardiovascular Research Institute, Department of Medicine (Cardiology), Albert Einstein College of Medicine, Bronx, New York
| | - Stefan Frantz
- Department of Internal Medicine I, University Hospital , Würzburg , Germany
| | - Robert G Gourdie
- Center for Heart and Regenerative Medicine Research, Virginia Tech Carilion Research Institute , Roanoke, Virginia
| | - Jeffrey W Holmes
- Department of Biomedical Engineering, University of Virginia Health System , Charlottesville, Virginia
| | - Steven P Jones
- Department of Medicine, Institute of Molecular Cardiology, Diabetes and Obesity Center, University of Louisville , Louisville, Kentucky
| | - Robert A Kloner
- HMRI Cardiovascular Research Institute, Huntington Medical Research Institutes , Pasadena, California.,Division of Cardiovascular Medicine, Keck School of Medicine, University of Southern California , Los Angeles, California
| | - David J Lefer
- Cardiovascular Center of Excellence, Louisiana State University Health Science Center , New Orleans, Louisiana
| | - Ronglih Liao
- Harvard Medical School , Boston, Massachusetts.,Division of Genetics and Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women's Hospital , Boston, Massachusetts
| | - Elizabeth Murphy
- Systems Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health , Bethesda, Maryland
| | - Peipei Ping
- National Institutes of Health BD2KBig Data to Knowledge (BD2K) Center of Excellence and Department of Physiology, Medicine and Bioinformatics, University of California , Los Angeles, California
| | - Karin Przyklenk
- Cardiovascular Research Institute and Departments of Physiology and Emergency Medicine, Wayne State University School of Medicine , Detroit, Michigan
| | - Fabio A Recchia
- Institute of Life Sciences, Scuola Superiore Sant'Anna, Fondazione G. Monasterio, Pisa , Italy.,Cardiovascular Research Center, Lewis Katz School of Medicine, Temple University , Philadelphia, Pennsylvania
| | - Lisa Schwartz Longacre
- Heart Failure and Arrhythmias Branch, Division of Cardiovascular Sciences, National Heart, Lung, and Blood Institute, National Institutes of Health , Bethesda, Maryland
| | - Crystal M Ripplinger
- Department of Pharmacology, School of Medicine, University of California , Davis, California
| | - Jennifer E Van Eyk
- The Smidt Heart Institute, Department of Medicine, Cedars Sinai Medical Center , Los Angeles, California
| | - Gerd Heusch
- Institute for Pathophysiology, West German Heart and Vascular Center, University of Essen Medical School , Essen , Germany
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2
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Bayeva M, Sawicki KT, Butler J, Gheorghiade M, Ardehali H. Molecular and cellular basis of viable dysfunctional myocardium. Circ Heart Fail 2014; 7:680-91. [PMID: 25028350 DOI: 10.1161/circheartfailure.113.000912] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Marina Bayeva
- From the Division of Cardiology, Department of Medicine, Northwestern University School of Medicine, Chicago, IL (M.B., K.T.S., M.G., H.A.); and Division of Cardiology, Department of Medicine, Emory University School of Medicine, Atlanta, GA (J.B.)
| | - Konrad Teodor Sawicki
- From the Division of Cardiology, Department of Medicine, Northwestern University School of Medicine, Chicago, IL (M.B., K.T.S., M.G., H.A.); and Division of Cardiology, Department of Medicine, Emory University School of Medicine, Atlanta, GA (J.B.)
| | - Javed Butler
- From the Division of Cardiology, Department of Medicine, Northwestern University School of Medicine, Chicago, IL (M.B., K.T.S., M.G., H.A.); and Division of Cardiology, Department of Medicine, Emory University School of Medicine, Atlanta, GA (J.B.)
| | - Mihai Gheorghiade
- From the Division of Cardiology, Department of Medicine, Northwestern University School of Medicine, Chicago, IL (M.B., K.T.S., M.G., H.A.); and Division of Cardiology, Department of Medicine, Emory University School of Medicine, Atlanta, GA (J.B.)
| | - Hossein Ardehali
- From the Division of Cardiology, Department of Medicine, Northwestern University School of Medicine, Chicago, IL (M.B., K.T.S., M.G., H.A.); and Division of Cardiology, Department of Medicine, Emory University School of Medicine, Atlanta, GA (J.B.).
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Fernandez SF, Ovchinnikov V, Canty JM, Fallavollita JA. Hibernating myocardium results in partial sympathetic denervation and nerve sprouting. Am J Physiol Heart Circ Physiol 2012; 304:H318-27. [PMID: 23125211 DOI: 10.1152/ajpheart.00810.2011] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Hibernating myocardium due to chronic repetitive ischemia is associated with regional sympathetic nerve dysfunction and spontaneous arrhythmic death in the absence of infarction. Although inhomogeneity in regional sympathetic innervation is an acknowledged substrate for sudden death, the mechanism(s) responsible for these abnormalities in viable, dysfunctional myocardium (i.e., neural stunning vs. sympathetic denervation) and their association with nerve sprouting are unknown. Accordingly, markers of sympathetic nerve function and nerve sprouting were assessed in subendocardial tissue collected from chronically instrumented pigs with hibernating myocardium (n = 18) as well as sham-instrumented controls (n = 7). Hibernating myocardium exhibited evidence of partial sympathetic denervation compared with the normally perfused region and sham controls, with corresponding regional reductions in tyrosine hydroxylase protein (-32%, P < 0.001), norepinephrine uptake transport protein (-25%, P = 0.01), and tissue norepinephrine content (-45%, P < 0.001). Partial denervation induced nerve sprouting with regional increases in nerve growth factor precursor protein (31%, P = 0.01) and growth associated protein-43 (38%, P < 0.05). All of the changes in sympathetic nerve markers were similar in animals that developed sudden death (n = 9) compared with electively terminated pigs with hibernating myocardium (n = 9). In conclusion, sympathetic nerve dysfunction in hibernating myocardium is most consistent with partial sympathetic denervation and is associated with regional nerve sprouting. The extent of sympathetic remodeling is similar in animals that develop sudden death compared with survivors; this suggests that sympathetic remodeling in hibernating myocardium is not an independent trigger for sudden death. Nevertheless, sympathetic remodeling likely contributes to electrical instability in combination with other factors.
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Affiliation(s)
- Stanley F Fernandez
- Center for Research in Cardiovascular Medicine, University at Buffalo, Buffalo, NY 14203, USA
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Tu C, Li J, Young R, Page BJ, Engler F, Halfon MS, Canty JM, Qu J. Combinatorial peptide ligand library treatment followed by a dual-enzyme, dual-activation approach on a nanoflow liquid chromatography/orbitrap/electron transfer dissociation system for comprehensive analysis of swine plasma proteome. Anal Chem 2011; 83:4802-13. [PMID: 21491903 DOI: 10.1021/ac200376m] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The plasma proteome holds enormous clinical potential, yet an in-depth analysis of the plasma proteome remains a daunting challenge due to its high complexity and the extremely wide dynamic range in protein concentrations. Furthermore, existing antibody-based approaches for depleting high-abundance proteins are not adaptable to the analysis of the animal plasma proteome, which is often essential for experimental pathology/pharmacology. Here we describe a highly comprehensive method for the investigation of the animal plasma proteome which employs an optimized combinatorial peptide ligand library (CPLL) treatment to reduce the protein concentration dynamic range and a dual-enzyme, dual-activation strategy to achieve high proteomic coverage. The CPLL treatment enriched the lower abundance proteins by >100-fold when the samples were loaded in moderately denaturing conditions with multiple loading-washing cycles. The native and the CPLL-treated plasma were digested in parallel by two enzymes (trypsin and GluC) carrying orthogonal specificities. By performing this differential proteolysis, the proteome coverage is improved where peptides produced by only one enzyme are poorly detectable. Digests were fractionated with high-resolution strong cation exchange chromatography and then resolved on a long, heated nano liquid chromatography column. MS analysis was performed on a linear triple quadrupole/orbitrap with two complementary activation methods (collisionally induced dissociation (CID) and electron transfer dissociation). We applied this optimized strategy to investigate the plasma proteome from swine, a prominent animal model for cardiovascular diseases (CVDs). This large-scale analysis results in identification of a total of 3421 unique proteins, spanning a concentration range of 9-10 orders of magnitude. The proteins were identified under a set of commonly accepted criteria, including a precursor mass error of <15 ppm, Xcorr cutoffs, and ≥2 unique peptides at a peptide probability of ≥95% and a protein probability of ≥99%, and the peptide false-positive rate of the data set was 1.8% as estimated by searching the reversed database. CPLL treatment resulted in 55% more identified proteins over those from native plasma; moreover, compared with using only trypsin and CID, the dual-enzyme/activation approach enabled the identification of 2.6-fold more proteins and substantially higher sequence coverage for most individual proteins. Further analysis revealed 657 proteins as significantly associated with CVDs (p < 0.05), which constitute five CVD-related pathways. This study represents the first in-depth investigation of a nonhuman plasma proteome, and the strategy developed here is adaptable to the comprehensive analysis of other highly complex proteomes.
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Affiliation(s)
- Chengjian Tu
- Department of Pharmaceutical Sciences, State University of New York at Buffalo, Buffalo, New York 14260, USA
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Jameel MN, Li Q, Mansoor A, Xiong Q, Swingen C, Zhang J. Long-term preservation of myocardial energetic in chronic hibernating myocardium. Am J Physiol Heart Circ Physiol 2010; 300:H836-44. [PMID: 21131472 DOI: 10.1152/ajpheart.00540.2010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
We previously reported that the myocardial energetic state, as defined by the ratio of phosphocreatine to ATP (PCr/ATP), was preserved at baseline (BL) in a swine model of chronic myocardial ischemia with mild reduction of myocardial blood flow (MBF) 10 wk after the placement of an external constrictor on the left anterior descending coronary artery. It remains to be seen whether this stable energetic state is maintained at a longer-term follow-up. Hibernating myocardium (HB) was created in minipigs (n = 7) by the placement of an external constrictor (1.25 mm internal diameter) on the left anterior descending coronary artery. Function was assessed with MRI at regular intervals until 6 mo. At 6 mo, myocardial energetic in the HB was assessed by (31)P-magnetic resonance spectrometry and myocardial oxygenation was examined from the deoxymyoglobin signal using (1)H-magnetic resonance spectrometry during BL, coronary vasodilation with adenosine, and high cardiac workload with dopamine and dobutamine (DpDb). MBF was measured with radiolabeled microspheres. At BL, systolic thickening fraction was significantly lower in the HB compared with remote region (34.4 ± 9.4 vs. 50.1 ± 10.7, P = 0.006). This was associated with a decreased MBF in the HB compared with the remote region (0.73 ± 0.08 vs. 0.97 ± 0.07 ml · min(-1) · g, P = 0.03). The HB PCr/ATP at BL was normal. DpDb resulted in a significant increase in rate pressure product, which caused a twofold increase in MBF in the HB and a threefold increase in the remote region. The systolic thickening fraction increased with DpDb, which was significantly higher in the remote region than HB (P < 0.05). The high cardiac workload was associated with a significant reduction in the HB PCr/ATP (P < 0.02), but this response was similar to normal myocardium. Thus HB has stable BL myocardial energetic despite the reduction MBF and regional left ventricular function. More importantly, HB has a reduced contractile reserve but has a similar energetic response to high cardiac workload like normal myocardium.
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Affiliation(s)
- Mohammad Nurulqadr Jameel
- Department of Medicine, University of Minnesota Medical School, University of Minnesota Medical School, Minneapolis, Minnesota 55455, USA
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Waller C, Engelhorn T, Hiller KH, Heusch G, Ertl G, Bauer WR, Schulz R. Impaired resting perfusion in viable myocardium distal to chronic coronary stenosis in rats. Am J Physiol Heart Circ Physiol 2005; 288:H2588-93. [PMID: 15665053 DOI: 10.1152/ajpheart.01060.2004] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Chronic coronary artery stenosis results in patchy necrosis in the dependent myocardium and impairs global and regional left ventricular (LV) function in rats in vivo. The aim of the present study was to compare regional myocardial blood flow (RMBF) and function (F) in poststenotic myocardium by using magnetic resonance imaging (MRI) and to compare MRI blood flow changes to histological alterations to assess whether RMBF in the viable poststenotic tissue remains normal. MRI was performed in 11 anesthetized Wistar rats with 2-wk stenosis of the left coronary artery. Postmortem, the extent of fibrotic tissue was quantified. Poststenotic RMBF was significantly reduced to 2.21 ± 0.30 ml·g−1·min−1 compared with RMBF in the remote myocardium (4.05 ± 0.50 ml·g−1·min−1). A significant relationship between the poststenotic RMBF (%remote area) and the poststenotic F (%remote myocardium) was calculated ( r = 0.61, P < 0.05). Assuming perfusion in scar tissue to be 32 ± 5% of perfusion of remote myocardium, as measured in five additional rats, and that in remote myocardium to be 114 ± 25% of that in normal myocardium, as assessed in five sham rats, the calculated perfusion in partially fibrotic tissue samples (35.7 ± 5.2% of analyzed area) was 2.88 ± 0.18 ml·g−1·min−1, whereas measured MRI perfusion was only 1.86 ± 0.24 ml·g−1·min−1 ( P < 0.05). These results indicate that resting perfusion in viable poststenotic myocardium is moderately reduced. Alterations in global and regional LV function are therefore secondary to both patchy fibrosis and reduced resting perfusion.
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Affiliation(s)
- Christiane Waller
- Universitätsklinik Würzburg, Medizinische Klinik, Josef-Schneider-Strasse 2, 97080 Würzburg, Germany.
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Slart RHJA, Bax JJ, de Boer J, Willemsen ATM, Mook PH, Oudkerk M, van der Wall EE, van Veldhuisen DJ, Jager PL. Comparison of 99mTc-sestamibi/18FDG DISA SPECT with PET for the detection of viability in patients with coronary artery disease and left ventricular dysfunction. Eur J Nucl Med Mol Imaging 2005; 32:972-9. [PMID: 15824927 DOI: 10.1007/s00259-005-1785-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2004] [Accepted: 02/01/2005] [Indexed: 11/26/2022]
Abstract
PURPOSE Dual-isotope simultaneous acquisition (DISA) single-photon emission computed tomography (SPECT) is an attractive technique as it permits assessment of both myocardial glucose metabolism and perfusion within a single session, but few data on its accuracy for the assessment of viability are available as yet. In the present study, DISA SPECT was compared with positron emission tomography (PET) for the detection of myocardial viability in normal and dysfunctional left ventricular (LV) myocardium. METHODS Fifty-eight patients with chronic coronary artery disease and LV dysfunction (LV ejection fraction 33+/-12%) were studied. Patients underwent a 1-day dipyridamole stress 99mTc-sestamibi/18F-fluorodeoxyglucose (18FDG) DISA SPECT and 13N-ammonia/18FDG PET protocol. Within 1 week, resting MRI was performed to assess contractile function. Comparison of PET and SPECT data was performed using both visual and quantitative analysis. RESULTS The correlation of normalised activities of the flow tracers 99mTc-sestamibi and 13N-ammonia was good (r = 0.82; p < 0.001). The correlation between the two 18FDG studies was also good (r = 0.83; p < 0.001). The agreement for the assessment of viability for all segments between DISA SPECT and PET was 82%, with a kappa-statistic of 0.59 (95% CI 0.53-0.64), without a significant difference; in dysfunctional segments only, the agreement was 82%, with a kappa-statistic of 0.63 (95% CI 0.56-0.70), without a significant difference. When the DISA SPECT data were analysed visually, the agreement between DISA SPECT and PET was 83%, with a kappa-statistic of 0.58 (95% CI 0.52-0.63), without a significant difference. Moreover, there was no significant difference between visual and quantitative DISA SPECT analysis for the detection of viability. CONCLUSION This study shows an overall good agreement between 99mTc-sestamibi/18FDG DISA SPECT and PET for the assessment of myocardial viability in patients with severe LV dysfunction. Quantitative or visual analysis of the SPECT data did not influence the agreement with PET, suggesting that visual assessment may be sufficient for clinical purposes.
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Affiliation(s)
- Riemer H J A Slart
- Department of Nuclear Medicine and Molecular Imaging, Groningen University Medical Center, Hanzeplein 1, P.O. Box 30001, 9700 RB, Groningen, The Netherlands.
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Bax JJ, van der Wall EE, Harbinson M. Radionuclide techniques for the assessment of myocardial viability and hibernation. Heart 2004; 90 Suppl 5:v26-33. [PMID: 15254006 PMCID: PMC1876321 DOI: 10.1136/hrt.2002.007575] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Affiliation(s)
- J J Bax
- Department of Cardiology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands.
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Southworth R, Garlick PB. Dobutamine responsiveness, PET mismatch, and lack of necrosis in low-flow ischemia: is this hibernation in the isolated rat heart? Am J Physiol Heart Circ Physiol 2003; 285:H316-24. [PMID: 12637355 DOI: 10.1152/ajpheart.00906.2002] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The clinical hallmarks of hibernating myocardium include hypocontractility while retaining an inotropic reserve (using dobutamine echocardiography), having normal or increased [18F]fluoro-2-deoxyglucose-6-phosphate (18FDG6P) accumulation associated with decreased coronary flow [flow-metabolism mismatch by positron emission tomography (PET)], and recovering completely postrevascularization. In this study, we investigated an isolated rat heart model of hibernation using experimental equivalents of these clinical techniques. Rat hearts (n = 5 hearts/group) were perfused with Krebs-Henseleit buffer for 40 min at 100% flow and 3 h at 10% flow and reperfused at 100% flow for 30 min (paced at 300 beats/min throughout). Left ventricular developed pressure fell to 30 +/- 8% during 10% flow and recovered to 90 +/- 7% after reperfusion. In an additional group, this recovery of function was found to be preserved over 2 h of reperfusion. Electron microscopic examination of hearts fixed at the end of the hibernation period demonstrated a lack of ischemic injury and an accumulation of glycogen granules, a phenomenon observed clinically. In a further group, hearts were challenged with dobutamine during the low-flow period. Hearts demonstrated an inotropic reserve at the expense of increased lactate leakage, with no appreciable creatine kinase release. PET studies used the same basic protocol in both dual- and globally perfused hearts (with 250MBq 18FDG in Krebs buffer +/- 0.4 mmol/l oleate). PET data showed flow-metabolism "mismatch;" whether regional or global, 18FDG6P accumulation in ischemic tissue was the same as (glucose only) or significantly higher than (glucose + oleate) control tissue (0.023 +/- 0.002 vs. 0.011 +/- 0.002 normalized counts. s-1x g-1x min-1, P < 0.05) despite receiving 10% of the flow. This isolated rat heart model of acute hibernation exhibits many of the same characteristics demonstrated clinically in hibernating myocardium.
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Fallavollita JA, Canty JM. Ischemic cardiomyopathy in pigs with two-vessel occlusion and viable, chronically dysfunctional myocardium. Am J Physiol Heart Circ Physiol 2002; 282:H1370-9. [PMID: 11893573 DOI: 10.1152/ajpheart.00138.2001] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A chronic left anterior descending coronary artery (LAD) stenosis leads to the development of hibernating myocardium with severe regional hypokinesis but normal global ventricular function after 3 mo. We hypothesized that two-vessel occlusion would accelerate the progression to hibernating myocardium and lead to global left ventricular (LV) dysfunction and heart failure. Pigs were instrumented with a fixed 1.5-mm constrictor on the proximal LAD and circumflex arteries. After 2 mo, there were no overt signs of right-heart failure and triphenyl tetrazolium chloride infarction was trivial (1.4 +/- 0.1% of the LV). Compared with shams, regional function [myocardial systolic excursion (DeltaWT); 2.1 +/- 0.3 vs. 4.6 +/- 0.4 mm, P < 0.05] and resting perfusion (0.90 +/- 0.13 vs. 1.32 +/- 0.09 ml small middle dot min(-1) small middle dot g(-1), P < 0.05) were reduced, consistent with hibernating myocardium. Pulmonary systolic (45.9 +/- 3.3 vs. 36.5 +/- 2.2 mmHg, P < 0.05) and wedge pressures (19.1 +/- 1.6 vs. 11.2 +/- 0.9 mmHg, P < 0.05) were increased with global ventricular dysfunction (ejection fraction 43 +/- 2 vs. 50 +/- 2%, P < 0.05). Early LV remodeling was present with increased cavity size and mass. Reductions in sarcoplasmic reticulum Ca(2+)-ATPase and phospholamban were confined to the dysfunctional LAD region with no change in calsequestrin. Thus combined stenoses of the LAD and circumflex arteries accelerate the development of hibernating myocardium and result in compensated heart failure.
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Affiliation(s)
- James A Fallavollita
- Department of Veterans Affairs, Western New York Health Care System, Buffalo 14215, USA
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11
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Giordano FJ, Gerber HP, Williams SP, VanBruggen N, Bunting S, Ruiz-Lozano P, Gu Y, Nath AK, Huang Y, Hickey R, Dalton N, Peterson KL, Ross J, Chien KR, Ferrara N. A cardiac myocyte vascular endothelial growth factor paracrine pathway is required to maintain cardiac function. Proc Natl Acad Sci U S A 2001; 98:5780-5. [PMID: 11331753 PMCID: PMC33290 DOI: 10.1073/pnas.091415198] [Citation(s) in RCA: 278] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The role of the cardiac myocyte as a mediator of paracrine signaling in the heart has remained unclear. To address this issue, we generated mice with cardiac myocyte-specific deletion of the vascular endothelial growth factor gene, thereby producing a cardiomyocyte-specific knockout of a secreted factor. The hearts of these mice had fewer coronary microvessels, thinned ventricular walls, depressed basal contractile function, induction of hypoxia-responsive genes involved in energy metabolism, and an abnormal response to beta-adrenergic stimulation. These findings establish the critical importance of cardiac myocyte-derived vascular endothelial growth factor in cardiac morphogenesis and determination of heart function. Further, they establish an adult murine model of hypovascular nonnecrotic cardiac contractile dysfunction.
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Affiliation(s)
- F J Giordano
- Cardiovascular Gene Therapy Program, Department of Medicine, Yale University School of Medicine, Boyer Center for Molecular Medicine, 295 Congress Avenue, Room 336C, New Haven, CT 06520, USA.
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Schulz R, Post H, Neumann T, Gres P, Lüss H, Heusch G. Progressive loss of perfusion-contraction matching during sustained moderate ischemia in pigs. Am J Physiol Heart Circ Physiol 2001; 280:H1945-53. [PMID: 11299193 DOI: 10.1152/ajpheart.2001.280.5.h1945] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
It is unclear whether perfusion-contraction matching (PCM) is maintained during prolonged myocardial ischemia. In 27 anesthetized pigs, left anterior descending coronary arterial inflow was reduced to decrease an anterior work index (WI) at 5 min of hypoperfusion by 40% and then maintained at this level for 12 or 24 h. With 12 h of hypoperfusion, the myocardium remained viable in 6 of 7 pigs (with triphenyltetrazolium chloride; TTC) and with 24 h of hypoperfusion in 5 of 11 pigs (TTC, histology). The reduction in WI to 62 +/- 4 and 62 +/- 3% of baseline in the two groups was matched to the reduction of transmural blood flow (TBF; microspheres) at 5 min of hypoperfusion, averaging 59 +/- 4 and 60 +/- 2% of baseline. With prolonged hypoperfusion, WI decreased to 30 +/- 5% at 12 h and 18 +/- 3% at 24 h; TBF remained unchanged (53 +/- 4 and 54 +/- 4%). The added calcium concentration required for the half-maximal increase in WI increased from 121 +/- 25 microg/ml blood at baseline to 192 +/- 26 microg/ml blood at 12 h of hypoperfusion. Thus, with hypoperfusion for 24 h, PCM is progressively lost, and calcium responsiveness is reduced.
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Affiliation(s)
- R Schulz
- Abteilung für Pathophysiologie, Zentrum für Innere Medizin des Universitätsklinikums Essen, 45122 Essen, Germany
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13
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Camici PG, Dutka DP. Repetitive stunning, hibernation, and heart failure: contribution of PET to establishing a link. Am J Physiol Heart Circ Physiol 2001; 280:H929-36. [PMID: 11179032 DOI: 10.1152/ajpheart.2001.280.3.h929] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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14
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Affiliation(s)
- R Schulz
- Department of Pathophysiology, Centre of Internal Medicine, University of Essen, School of Medicine, Hufelandstrasse 55, 45122 Essen, Germany
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Abstract
Identification of myocardial viability is of increasing clinical importance in managing patients with coronary artery disease and advanced left ventricular dysfunction. Although viable chronically dysfunctional myocardium is always the result of repetitive episodes of reversible ischemia, there may be multiple mechanisms responsible for the contractile dysfunction. Many patients have contractile dysfunction with normal resting perfusion, as determined by imaging, that is related to chronic myocardial stunning. Viability studies are generally unnecessary because normal resting perfusion would preclude significant fibrosis. The clinical problem arises in evaluating patients with depressed resting flow that can be due to hibernating myocardium or nontransmural infarction. In this circumstance viability studies are required to assess the likelihood of functional recovery after revascularization. Although hibernating myocardium was originally posited to develop in response to prolonged episodes of myocardial ischemia (experimentally termed "short-term hibernation"), subsequent studies have shown that this tenuous balance can only be maintained for a period of several hours before resulting in some degree of subendocardial infarction. More recent experimental studies have demonstrated that there is a progression from chronic stunning with normal flow to hibernating myocardium with reduced resting flow. This presumably arises from repetitive episodes of spontaneous ischemia that increase in frequency as the physiologic significance of a coronary stenosis progresses. Thus in this new paradigm reduced flow is a result, rather than the cause, of the contractile dysfunction. This review summarizes basic and clinical pathophysiologic studies supporting the claim that chronic stunning and hibernation are distinct entities that may represent opposite ends of a continuum of mechanisms in viable chronically dysfunctional myocardium.
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Affiliation(s)
- J M Canty
- Department of Veterans Affairs Western New York Health Care System and the Department of Medicine, University at Buffalo, School of Medicine and Biomedical Sciences, NY 14214, USA.
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