**3. Cardiomyopathy**

Cardiomyopathy is a group of structural disorders of the myocardium. Unlike other structural heart disorders such as coronary artery disease, valvular heart disease, and congenital heart disease. Cardiomyopathy is classified into three main types based on pathological features.

#### **3.1 Dilated cardiomyopathy**

#### *3.1.1 Abstract*

Dilated cardiomyopathy is a myocardial dysfunction causing heart failure in which ventricular dilatation and systolic dysfunction predominate. Symptoms include dyspnea, fatigue, and peripheral edema. Diagnosis is based on clinical findings, quantification of natriuretic peptide (BNP) levels, chest x-ray, echocardiography, and CMR. Treatment of dilated cardiomyopathy is based on etiology. If heart failure is advanced and severe, cardiac resynchronization therapy (CRT), implantable cardioverter defibrillator (ICD), moderate to severe regurgitation repair, LV assist device may be needed in the short-term or long-term and heart transplant [19]. Dilated cardiomyopathy can develop at any age but is more common in adults under age 50. In the United States, men are three times more likely to have the disease than women, and African-Americans are three times more likely to have the disease than whites; about 5 to 8 out of 100,000 people get it each year [20].

#### *3.1.2 Pathophysiology*

As primary cardiomyopathy, dilated cardiomyopathy has been identified in the absence of other disorders that can cause dilated cardiomyopathy, malformations such as severe coronary artery disease or hypertension, or valvular heart disease. In some patients, dilated cardiomyopathy is thought to progress from acute myocarditis (often viral etiology in most cases), followed by a latent phase, a stage of disseminated cell death, cardiomyocytes (causing an autoimmune response to virally altered cardiomyocytes), and fibrosis. Regardless of the cause, the myocardium dilates, enlarges, and enlarges to compensate [19, 21]. The disorder affects both the left and right ventricles in most patients but rarely affects only one ventricle. Thrombosis can form due to blood stagnation when time dilates and cardiac dysfunction is significant.

#### *3.1.3 Clinical diagnostic criteria*

Diagnosis of dilated cardiomyopathy is based on history, physical examination, and exclusion of other common causes of ventricular dysfunction (eg, hypertension, primary valvular disease, coronary artery disease) by the chest x-ray, electrocardiogram, echocardiography, and cardiac magnetic resonance imaging (CMR). Endocardial biopsies are performed in some cases. In cases of unknown etiology, family members are screened for cardiac dysfunction to detect early-onset heart disease, heart failure, or sudden death (such as echocardiography).

• Serological tests for Toxoplasma, Trigonoscuta cruzi, coxsackievirus, HIV, and echovirus may be performed in appropriate cases.

