Cardiomyopathies

Question 1

What is the classification of Cardiomyopathies?

Answer 1

• Primary
• Genetic
• Mixed
• Acquired
• Secondary Cardiomyopathies

Question 2

What are examples of Genetic Cardiomyopathies?

Answer 2

• Hypertrophic obstructive cardiomyopathy
• Arrhythmogenic right ventricular dysplasia

Question 3

What is Hypertrophic Obstructive Cardiomyopathy?

Answer 3

• Commonest cause of sudden death (leading cause in young athletes)
• Usually due to a mutation in the gene encoding β-myosin heavy chain protein

Question 4

What are echo findings for HOCM?

Answer 4

Echo findings include

• Mitral Regurgitaton
• Systolic anterior motion (SAM) of the anterior mitral valve
• Asymmetric septal hypertrophy

Question 5

What is Arrhythmogenic right ventricular dysplasia?

Answer 5

• Right ventricular myocardium is replaced by fatty and fibrofatty tissue
• Around 50% of patients have a mutation of one of the several genes which encode components of desmosome

Question 6

What is the pathophysiology of Dilated Cardiomyopathy?

Answer 6

• Dilated heart leading to systolic (+/- diastolic) dysfunction
• All 4 chambers affected but LV more so than RV

Question 7

What are the clinical features of Dilated Cardiomyopathy?

Answer 7

Clinical Features features include

• Arrhythmias
• Emboli
• Mitral regurgitation
• Absence of Congenital, Valvular or Ischaemic heart disease

Question 8

What are classic causes of Dilated Cardiomyoahty?

Answer 8

Classic causes include

• Alcohol
• Coxsackie B virus
• Wet beri beri (thiamine deficieny)
• Doxorubicin

Question 9

What are other cases of Dilated Cardiomypathy?

Answer 9

• Postpartum
• Hypertension
• Infections (HIV, diphtheria, parasitic)
• Endocrine
• Infiltrative (Haemochromatosis, sarcoidosis)
• Neuromuscular (Duchenne muscular dystrophy)
• Nutritional e.g. Kwashiorkor, pellagra, thiamine/selenium deficiency

Question 10

What are some exmaples of Acquired Cardiomyopathy?

Answer 10

• Takotsubo cardiomyopathy
• Peripartum cardiomyopathy

Question 11

What is the pathophysiology of Takotsubo Cardiomyopathy?

Answer 11

• Type of non-ischaemic cardiomyopathy associated with transient, apical ballooning of myocardium.
• Known as broken heart syndrome
• ‘Stress’-induced cardiomyopathy e.g. patient just found out family member dies then develops chest pain and features of heart failure

Question 12

What are the features of Takostubo Cardiomyopathy?

Answer 12

• Chest pain
• Features of heart failure
• ST elevation
• Normal coronary angiogram

Treated supportively

Question 13

What are some causes of Secondary Cardiomyopathy?

Answer 13

• Infective: Coxsackie B virus, Chagas disease
• Infiltrative: Amyloidosis
• Storage: Haemochromatosis
• Toxicity: Doxorubicin, Alcoholic cardiomyopathy
• Inflammatory (granulomatous): Sarcoidosis
• Endocrine: Diabetes mellitus, Thyrotoxicosis, Acromegaly
• Neuromuscular: Friedreich’s ataxia, Duchenne-Becker muscular dystrophy, Myotonic dystrophy
• Nutritional deficiencies: Beriberi (thiamine)
• Autoimmune: Systemic lupus erythematosis