Review Article
Physiologic Basis and Pathophysiologic Implications of the Diastolic Properties of the Cardiac Muscle
Table 1
Determinants of diastolic function and myocardial stiffness.
| Determinants of diastolic function |
| Myocardial relaxation | Load | Inactivation (calcium homeostasis, myofilaments, energetics) | Nonuniformity | Passive properties of ventricular wall | Myocardial stiffness | Wall thickness | Chamber geometry | Other determinants | Structures surrounding the ventricle (pericardium, lungs, remaining, cardiac chambers) | Left atrium, pulmonary veins and mitral valve | Heart rate |
| Determinants of myocardial stiffness |
| Cardiomyocytes | Ca2+ homeostasis | Diastolic calcium concentration: residual cross-bridges | Cytoskeleton | Microtubules (tubulin) and intermediate filaments (desmin): density and cellular stiffness | Myofilaments: actin and myosin (residual cross-bridges) | Titin: isoforms expression ratio; isoforms’ phosphorylation status | Extracellular matrix | Collagen: content, type, alignment, spatial distribution, cross-linking | Proteoglycans: putative role in interstitial water flow and content within the myocardium | Elastin: putative decrease in elastin/collagen ratio with increased myocardial stiffness |
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