Cardiomyopathy is a group of diseases that affect the heart muscle. These conditions primarily impact the structural and functional ability of the heart muscle to pump blood effectively, which can lead to heart failure and other complications. Cardiomyopathy can be classified into several main types based on the physical changes that occur in the heart and the mechanics of these changes:
1. Dilated Cardiomyopathy (DCM)
- Description: This is the most common form. The heart’s main pumping chamber, the left ventricle, is enlarged and weakened, impairing the heart’s ability to pump blood efficiently.
- Causes: It can be caused by genetic factors, viral infections, alcohol abuse, toxins, and the effects of chemotherapy drugs, among other reasons.
- Symptoms: Patients may experience symptoms of heart failure like breathlessness, fatigue, and swelling in the legs and ankles.
2. Hypertrophic Cardiomyopathy (HCM)
- Description: In HCM, the heart muscle becomes abnormally thick, particularly the ventricles, making it harder for the heart to pump blood.
- Causes: It is often inherited and is caused by mutations in genes that make the proteins of the heart muscle.
- Symptoms: Many people may have no symptoms, while others can have severe symptoms, including chest pain, palpitations, fainting, and potentially sudden cardiac death, especially in young athletes.
- Description: The least common type where the ventricles become stiff and rigid due to abnormal tissue, such as scar tissue, replacing the normal heart muscle, which restricts the heart’s ability to stretch and fill with blood properly.
- Causes: It can result from diseases such as amyloidosis or sarcoidosis that deposit abnormal substances in the heart, but often the cause is unknown.
- Symptoms: Symptoms include fatigue, swelling of the legs and feet, and difficulty breathing.
4. Arrhythmogenic Right Ventricular Dysplasia (ARVD)
- Description: A rare type of cardiomyopathy where heart muscle cells are progressively replaced with fatty and fibrous tissue, primarily affecting the right ventricle.
- Causes: It is typically inherited and is caused by genetic mutations.
- Symptoms: It can cause arrhythmias, heart palpitations, fainting spells, and sometimes sudden death.
5. Unclassified Cardiomyopathy
- Description: There are other forms of cardiomyopathy that don’t fit neatly into the above categories, often because of their rare or unique characteristics.
Cardiomyopathy can also be secondary to other conditions — meaning it develops because of another disease, condition, or factor. The classification helps guide the treatment and management approaches, which can vary significantly depending on the type of cardiomyopathy and its underlying cause.