Myocardial infarction A
myocardial infarction, also known as a heart attack, often result in the formation of fibrosis. Without blood flow to the myocardium, it is deprived of oxygen, causing tissue death and irreversible damage. The tissue destroyed by the infarction is replaced with non-functioning fibrosis, restoring some of the structural integrity of the organ but resulting in impaired myocardial function.
Coronary heart disease Coronary heart disease, also known as coronary artery disease, is one of the most common causes of myocardial damage, affecting over three million people in the United States. In coronary heart disease, the
coronary arteries narrow due to the buildup of
atheroma or fatty deposits on the vessel walls. The atheroma causes the blood flow of the arteries to be restricted. While surgical
laparoscopy still leaves myocardial scarring, the trauma seems to be less damaging then naturally occurring scarring.
Hypertension Chronic hypertension can lead to myocardial scarring by imposing persistent high pressure on heart walls. This stress causes
left ventricular hypertrophy, increasing
oxygen demand and potentially leading to micro-ischemia. Over time, these changes may result in fibrosis as the heart attempts to repair damaged tissue, impairing cardiac function.
Cardiomyopathies Cardiomyopathies, such as
dilated or
hypertrophic cardiomyopathy, are associated with myocardial scarring. These conditions alter heart muscle structure and function. Scarring may contribute to
heart failure or
arrhythmias.
Myocarditis Myocarditis, inflammation of the heart muscle often caused by
viral infections, can result in myocardial scarring. The
inflammatory response damages cardiac tissue, triggering repair processes that replace necrotic cells with fibrous tissue. This scarring may increase the risk of arrhythmias.
Cardiac toxins Exposure to
cardiotoxic substances, such as
chemotherapy drugs (e.g.,
anthracyclines),
alcohol, or
recreational drugs like
cocaine, can cause myocardial scarring due to
free radical damage, strand breakage of DNA in
cardiomyocytes. These toxins induce direct damage to heart muscle cells, leading to inflammation and fibrosis as the body attempts to repair the injured tissue.
Aging Aging is a natural contributor to myocardial scarring. Over time, cumulative stress from
oxidative damage, low-grade
inflammation, and
microvascular changes can lead to gradual fibrosis in the heart. This age-related scarring may reduce cardiac elasticity and contribute to
diastolic dysfunction in older individuals. == Formation ==