5th July 2026

Background

Cardiomyopathy describes distinct structural abnormalities in the heart muscle, causing various degrees of functional abnormalities where effective circulation is diminished. Cardiomyopathy is a broad term and can be divided into dilated (DCM), hypertrophic (HCM) – further divided into obstructive (⅔) and non-obstructive (⅓) – restrictive (RCM) and arrhythmogenic right ventricular cardiomyopathy (ARVC). It can be primary in nature and or secondary to pre-existing disease. Genetic cardiomyopathies tend to be autosomal dominant in nature.  Eventually, cardiomyopathy can result in heart failure. The varying subtypes of cardiomyopathy influence specific management, potential complications, and long-term prognosis. 

• ARVC is when the replacement of myocardial tissue with fibrofatty tissue in the right ventricle results in arrhythmias. 
• DCM is ​​left ventricular or biventricular dilation and impaired contraction, unexplained by abnormal loading conditions or coronary artery disease.
• HCM is when there is hypertrophy of the ventricles. When it becomes obstructive, it is known as HOCM.
• RCM is a functional classification where the occurrence of left ventricular myocardial stiffness results in adverse filling of the left ventricle.

Risk factors

• infections (including viral hepatitis and HIV)
• metabolic and endocrine conditions (including thyroid disease, diabetes and obesity)
• infiltrative diseases (including sarcoidosis and amyloidosis)
• myopathies (including Duchenne muscular dystrophy)
• cocaine use/amphetamines
• stress
• excess alcohol consumption
• radiation exposure
• chemotherapy
• family history of cardiomyopathy or heart conditions