Cardiac mechanical efficiency is preserved in primary cardiac hypertrophy despite impaired mechanical function
نویسندگان
چکیده
منابع مشابه
Cardiac hypertrophy. Mechanical, neural, and endocrine dependence.
C ardiac hypertrophy usually follows an increase in work load that is imposed on the heart. Usually, greater work is due to increased afterload in patients with hypertension or after myocardial infarction in which the remaining muscle must assume the work of the segment that was lost as a result of myocardial cell death and scar formation. In some instances, increased pressure or volume work of...
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The aim of this study was to determine whether the initial mechanical efficiency (ratio of work output to initial metabolic cost) of isolated cardiac muscle is over 60%, as has been reported previously, or whether it is approximately 30%, as suggested by an estimate based on the well-established net mechanical efficiency (ratio of work output to total, suprabasal energy cost) of 15%. Determinat...
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OBJECTIVES So many clinical trials of positive inotropes have failed, that it is now axiomatic that agents that increase cAMP are deleterious to the failing heart. An alternative strategy is to alter myocardial Ca(2+) handling or myofilament response to Ca(2+) using agents that do not affect cAMP. Although left ventricular (LV) function is tightly linked to adenylyl cyclase (AC) activity, the b...
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Cardiac function relies on the ability of the myocytes to develop force and shorten, as well as on the geometry of the heart, which translates shortening into stroke volume and force per cell into pressure in the lumen of the chambers. The requirements of circulation are met by adjustment of heart rate and power output by the myocytes. The heart adapts acutely to a hemodynamic load by increasin...
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The mechanical properties of trabecular muscles from the hearts of 77 rats subjected to aortic arch constriction were compared with those from 77 unoperated and sham-operated control animals at 1, 3, 7, 14, and 28 days after operation. Significant hypertrophy, as evidenced by an increase in left ventricle to body weight ratio, was first seen at three days ( P < 0 . 0 2 ) , reached a maximum of ...
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ژورنال
عنوان ژورنال: Journal of General Physiology
سال: 2021
ISSN: 0022-1295,1540-7748
DOI: 10.1085/jgp.202012841