DEFINITION, PREVALENCE, ETIOLOGY

DEFINITION 

• Primary disease of the heart muscle
• 4 main types: dilated (congestive), hypertrophic, restrictive, arrhythmogenic right ventricular cardiomyopathy

PREVALENCE

• Hypertrophic cardiomyopathy: the most common form
• Restrictive cardiomyopathy: rare
• Arrhythmogenic right ventricular cardiomyopathy: rare

ETIOLOGY 

Dilated cardiomyopathy:

• Idiopathic (>50% cases)
• Familial (20%)
• Cardiovascular
• Alcohol
• Infections: Coxsackie virus
• Endocrine: thyrotoxicosis
• Cardiotoxic drugs
• Pregnancy
• Connective tissue disease: SLE, systemic sclerosis
• Other: sarcoidosis, amyloidosis, hemochromatosis, muscular dystrophy, malignancies

Hypertrophic cardiomyopathy:

• Autosomal dominant inheritance – It is important to look at the family history in these patients
• 50% sporadic cases

Restrictive cardiomyopathy:

• Hemochromatosis
• Amyloidosis
• Sarcoidosis

Arrhythmogenic right ventricular cardiomyopathy:

• Genetic mutation

SIGNS & SYMPTOMS 

Dilated cardiomyopathy:

• Heart failure

Arrhythmias

• Syncope Peripheral embolism

Hypertrophic cardiomyopathy:

• Palpitations
• Breathlessness
• Chest pain
• Murmurs
• Fainting/collapse