Cardiomyopathy

Question 1

Define cardiomyopathy

What are the different types?

Answer 1

Diseases of the heart muscle or myocardium
• Hypertrophic – ventricular hypertrophy in the absence of abnormal loading
• Dilated – dilated LV with poor contraction
• Restrictive – rigid myocardium

Question 2

What are the causes/risk factors of cardiomyopathy?

Answer 2

Hypertrophic
• Genetic (autosomal dominant) e.g. beta-myosin, troponin T

Dilated
• Post-viral myocarditis
• Alcohol
• Drugs
• Familial (autosomal dominant)
• Hyperthyroidism
• Haemochromatosis
• Peripartum

Restrictive
• Amyloidosis
• Sarcoidosis
• Haemochromatosis

Question 3

What are the symptoms of cardiomyopathy?

Answer 3

Hypertrophic
• Asymptomatic
• SOB
• Syncope
• Angina

Dilated
• Symptoms of biventricular heart failure
• SOB

Restrictive
• SOB
• Fatigue
• Ankle swelling
• Ascites

Question 4

What are the signs of cardiomyopathy?

Answer 4

Hypertrophic
• Jerky carotid pulse
• Double apex beat
• Ejection systolic murmur
• S4

Dilated
• Raised JVP
• Displaced apex beat
• S3
• Functional MR/TR

Restrictive
• Raised JVP (Kussmaul’s sign – JVP increases on inspiration)
• S3
• Ascites
• Oedema
• Heaptomegaly

Question 5

What investigations are carried out for cardiomyopathy?

Answer 5

• CXR - May show cardiomegaly or signs of heart failure
• ECG -
All types: Non-specific ST changes, conduction defects, arrhythmias
Hypertrophic: Left-axis deviation, signs of left ventricular hypertrophy, Q waves in inferior and lateral leads
Restrictive: Low voltage complexes

• Echocardiography
Dilated: Dilated ventricles with global hypokinesia,
Hypertrophic: Ventricular hypertrophy (asymmetrical septal hypertrophy)
Restrictive: Non-dilated non-hypertrophied ventricles, Atrial enlargement, Preserved systolic function, Diastolic dysfunction , Granular or sparkling appearance of myocardium in amyloidosis
• Cardiac Catheterisation
• Endomyocardial Biopsy
• Pedigree or Genetic Analysis