PATHOGENETIC ROLE OF MYOCARDIAL FIBROSIS: FOCUS ON EXTRACELLULAR MATRIX

The main cardiovascular diseases affect the processes of myocardial remodeling, which further contributes to the formation of systolic or diastolic heart dysfunction. The formation of myocardial dysfunction is primarily associated with left ventricular hypertrophy when under hemodynamic loading, firstly, wall rigidity increases, secondly, myocardial fibrosis is formed. The latter is one of the key factors of the hypertrophic process caused by the accumulation of collagen, which leads to a aggravation of the left ventricle relaxation processes. Cardiac remodeling is defined as a group of molecular, cellular, and interstitial changes that are clinically manifested by alterations in the size, shape, and function of heart as a result of the heart muscle injury. It has been determined that fibrosis is an early morphological sign of injury in patients with left ventricular overload, as well as a factor in the development of diastolic and systolic dysfunctions. Compensatory left ventricular hypertrophy transforms into heart failure due to the fibrosis development. In hypertrophy the content of elastic collagen type III decreases and rigid collagen type I increases. The essential role of the extracellular matrix in myocardial fibrosis formation is emphasized. Cardiac fibrosis is a process of pathological remodeling of the extracellular matrix, which leads to abnormalities in its composition and dysfunction of the heart muscle. The extracellular matrix plays a key role in organogenesis and post−traumatic healing in tissue injuries. The study of intercellular interactions of the extracellular matrix will provide a better understanding of the mechanisms of changes in geometry and function of the heart, and investigation of the activity of matrix components will open new opportunities for targeted therapeutic effects on molecular mechanisms of cardiac remodeling. Key words: diastolic dysfunction, extracellular matrix, myocardial fibrosis, cardiomyocytes, fibroblasts.