Evaluation of myocardial relaxation in conditions of cardiac remodeling.

The term cardiodynamics refers to dynamic events associated with cardiac contraction and relaxation. The occurring wave of excitement spreads very quickly along the entire atrial musculature and after a brief AV retention it affects all muscle cells of the ventricles. Excitation, that is, the increase in action potentials, precedes the contraction of the myocardium, which follows the "all or none" rule. Each contraction results in relaxation of the myocardium, so that the contraction and relaxation cycles continually follow each other in succession. The entire cardiodynamics, hemnodinamics, i.e., signaling mechanisms of the heart are altered in the remodeling (alternation) condition of the left ventricular myocardium, i.e., the musculature and the whole arterial wall. Remodeling of the cardiac wall and layers of the arterial wall is a negative factor, because it leads to disturbances of the cardiac contraction and relaxation cycles and incites progression of the arterial hypertension, emergence of atherosclerosis and arterial stenosis. Today, the genetic base of the cardiac remodeling is the object of intensive studies. Cardiomyopathies are primary disorders of the myocardium associated with abnormalities of the cardiac wall thickness, the size of chambers, contractions, relaxations, signal conduct and rhythm. They are the major cause of morbidity and mortality for all age groups. Mechanisms of these events on the molecular level will be discussed in the following study.