Passive stiffness of pressure-induced hypertrophied cat myocardium
| Autor: | R D Potter, J F Williams |
|---|---|
| Rok vydání: | 1981 |
| Předmět: |
Time Factors
Physiology Alpha (ethology) Blood Pressure Cardiomegaly Strain (injury) Muscle hypertrophy Stress (mechanics) Nuclear magnetic resonance medicine Animals Beta (finance) Passive stiffness Chemistry Stiffness Heart Anatomy Papillary Muscles medicine.disease Myocardial Contraction Elasticity Myocardial hypertrophy Cats Stress Mechanical medicine.symptom Cardiology and Cardiovascular Medicine |
| Zdroj: | Circulation Research. 49:211-215 |
| ISSN: | 1524-4571 0009-7330 |
| DOI: | 10.1161/01.res.49.1.211 |
| Popis: | The effect of myocardial hypertrophy on passive stiffness was determined from the stress (sigma)-strain relationship of right ventricular papillary muscles from 18 pulmonary artery-banded and 21 non-banded cats. By use of Lagrangian strain, (1-lo)lo is initial muscle length, and instantaneous stress elastic constants beta and alpha were calculated from the equation sigma = alpha(ebeta epsilon - 1). Elastic stiffness (d sigma/d epsilon) was determined from the formula d sigma/d epsilon = beta alpha + alpha beta. Banding produced an average increase in RV mass of 70%. Beta averaged 14.2 +/- 0.9 (SEM) and 16.0 +/- 0.8 in the non-hypertrophied and hypertrophied muscles, respectively (NS). However, elastic stiffness was significantly greater in hypertrophied muscles over the entire stress range. Contractile function varied widely among hypertrophied muscles but was not related to changes in stiffness. Thus, moderate degrees of pressure-induced hypertrophy are associated with a modest increase in the passive stiffness properties of the muscle, independent of changes in contractile function. |
| Databáze: | OpenAIRE |
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