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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