| Skeletal muscle myosin heavy chains in heart failure: correlation between magnitude of the isozyme shift, exercise capacity, and gas exchange measurements. | |
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MedLine Citation:
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PMID: 9453532 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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BACKGROUND: Patients with congestive heart failure (CHF) have a reduced exercise capacity because of the early appearance of fatigue and dyspnea. Qualitative changes in the skeletal muscle composition and metabolism can be responsible for the origin of symptoms METHODS: We correlated the myosin heavy chain (MHC) composition of the gastrocnemius in 20 patients with different degrees of CHF to NYHA class, diuretic consumption, echocardiographic parameters, and expiratory gases measured during cardiopulmonary exercise testing. MHC composition was determined electrophoretically in skeletal muscle needle microbiopsies and the percent distribution was calculated by densitometry. Maximal cardiopulmonary exercise testing was performed on a treadmill with a modified Naughton protocol. A capnograph was used. RESULTS: There was no correlation between ejection fraction, left ventricular end systolic diameter, left ventricular end diastolic diameter, and MHC composition. We found a significant positive correlation between the percentage of MHC 1 (slow aerobic isoform) and NYHA class (r2 = 0.62, p < 0.0001), peak VO2 (r2 = 0.5, p < 0.0004), ventilatory threshold (VT) (r2 = 0.33, p = 0.008) and O2 pulse (peak VO2/HR) (r2 = 0.40, p = 0.003). There was a negative correlation between both MHC2a (fast oxidative) and MHC2b (fast glycolytic) with peak VO2 (r2 = 0.38, p = 0.004 and r2 = 0.37, p = 0.004, respectively), VT (r2 = 0.2, p = 0.046 and r2 = 0.34, p = 0.007, respectively), and O2 pulse (peak VO2/HR) (r2 = 0.39, p = 0.003 and r2 = 0.23, p = 0.03). NYHA class was also correlated positively with MHC2a and MHC2b (r2 = 0.46, p = 0.001 and r2 = 0.41, p < 0.006, respectively) and negatively with the same clinical and functional parameters. CONCLUSIONS: The correlation between the magnitude of the MHC shift from the slow aerobic to the fast glycolytic and fast oxidative with both functional and objective measurements of exercise capacity (peak VO2, VT, O2 pulse) seem to suggest that changes in skeletal muscle composition may play a determining role in exercise tolerance in patients with CHF. |
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Authors:
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G Vescovo; F Serafini; L Dalla Libera; C Leprotti; L Facchin; P Tenderini; G B Ambrosio |
Publication Detail:
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Type: Journal Article |
Journal Detail:
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Title: American heart journal Volume: 135 ISSN: 0002-8703 ISO Abbreviation: Am. Heart J. Publication Date: 1998 Jan |
Date Detail:
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Created Date: 1998-02-10 Completed Date: 1998-02-10 Revised Date: 2007-11-15 |
Medline Journal Info:
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Nlm Unique ID: 0370465 Medline TA: Am Heart J Country: UNITED STATES |
Other Details:
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Languages: eng Pagination: 130-7 Citation Subset: AIM; IM |
Affiliation:
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First Department of Internal Medicine, Venice City Hospital, Italy. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Aged Exercise Test Exercise Tolerance* Heart Failure / metabolism, physiopathology* Hemodynamics Humans Male Middle Aged Muscle, Skeletal / chemistry* Myosin Heavy Chains / analysis* Oxygen Consumption Pulmonary Gas Exchange Respiration |
| Chemical | |
Reg. No./Substance:
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0/Myosin Heavy Chains |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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