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This study tested the hypothesis that with hypertrophy, the proportion, distribution, and structural alignment of fibrillar collagen are important determinants of myocardial stiffness. Toward this end, the collagen volume fraction (morphometry), the transmural or subendocardial distribution of collagen, and the structural arrangement of fibrillar collagens(More)
Cardiac muscle is tethered within a fibrillar collagen matrix that serves to maximize force generation. In the human pressure-overloaded, hypertrophied left ventricle, collagen concentration is known to be increased; however, the structural and biochemical remodeling of collagen and its relation to cell necrosis and myocardial mechanics is less clear.(More)
Muscular work requires the integration of cardiopulmonary mechanisms for gas exchange and O2 delivery. In patients with chronic cardiac failure, the response of these mechanisms may be impaired, and the pattern of O2 utilization (VO2) and gas exchange during exercise would thus provide an objective assessment of the severity of heart failure. Accordingly,(More)
This study had two objectives: (a) to determine the accumulation of collagen and its structural remodelling in the hypertrophied rat left ventricle after 4 and 8 weeks of abdominal aorta banding; and (b) to correlate these findings with the diastolic stress-strain relation of the intact myocardium. In comparison to age and sex matched controls, the collagen(More)
To determine the interrelationships between ejecting and isovolumic force-length relations and the extent to which the left ventricle will shorten, data obtained in 27 isolated, servo-regulated hearts were examined. For each heart a series of contractions, variably loaded (delta L) were derived for a thickwalled sphere and normalized by the cross-sectional(More)
A nonlinear theory of large elastic deformations of the aortic tissue has been developed. The wall tissue has been considered to be incompressible and curvilinearly orthotropic. The strain energy density function for the tissue is expressed as a polynomial in the circumferential and longitudinal Green-St. Venant strains. Limiting application to states of(More)
Cardiotonic agents may prove useful in the long-term treatment of chronic heart failure provided myocardial efficiency is enhanced and clinical status is improved. Accordingly, the short-term hemodynamic and clinical response to the phosphodiesterase inhibitor, MDL 17043, was evaluated. Intravenous increments of 0.05 mg/kg (maximal total 3 mg/kg) were given(More)
Left ventricular hypertrophy (LVH) in rats with genetic hypertension is accompanied by abnormal myocardial diastolic stiffness and impaired coronary reserve. Whether these functional defects are related to a structural remodeling of the myocardium that includes an interstitial and perivascular fibrosis, myocyte hypertrophy, and medial thickening of(More)