Cardiomyopathies

Question 1

What is acute myocarditis?

Outline the;

• Causes
• Signs & symptoms
• Diagnosis

Answer 1

Acute inflammation of myocardium.

Causes;

• Idiopathic (>50%)
• Viral (europe)
• Chagas’ disease (protozoan, worldwide)
• Bacterial, drugs, immunologic

Signs & symptoms;

• Fatigue, fever
• Dyspnoea
• Chest pain, palpitations, tachycardia
  
  • Soft S₁& S₄ gallop

Diagnosis;

• ECG; ST up or down, T wave inversion, atrial arrhythmias, transient AV block
• +ve Troponin I or T confirms diagnosis (if no MI.. obv)
• -ve antimyosin scintigraphy excludes it

Question 2

What is dilated cardiomyopathy?

Outline the;

• Causes
• Signs & symptoms
• Diagnosis

Answer 2

Dilated, flabby heart of unknown cause.

Associations;

• Any myocarditis
• Alcohol
• Thyrotoxicosis
• Congenital
• Hypertension

Signs & symptoms;

• Heart failure signs

Diagnosis;

• Bloods;
  
  • Plasma BNP is sensitive & specific for HF
  • Low Na⁺ indicates poor prognosis
• CXR (ABCDE of HF);
  
  • Alveolar shadowing (bat’s wings)
  • Kerley B lines (diffuse interstiail oedema)
  • Cardiomegaly
  • Dilated prominent upper lobe veins
  • Pleural Effusion
• ECG;
  
  • Tachycardia, non-specific T wave changes, poor R wave progression
• Echo;
  
  • Globally dilated hypokinetic heart & low ejection fraction
  • Look for thrombus

Question 3

What is hypertrophic cardiomyopathy?

Outline the;

• Causes
• Signs & symptoms
• Diagnosis

Answer 3

Myocardium is hypertrophied without any obvious cause. Causes left ventricular outflow tract obstruction due to septal hypertrophy.

Causes;

• Autosomal dominant inheritance
• 70%; encoding B-myosin, a-tropomyosin, toponin T

Signs & symptoms;

• Sudden death
• Chest pain/ angina, palpitations, tachycardia, syncope
• Jerky pulse; a wave in JVP
• Double apex beat
• Systolic thril at lower left sternal edge
• Harsh ejection systolic murmur (aortic stenosis due to septal enlargement)

Diagnosis;

• ECG;
  
  • LVH
  • Deep Q waves (inf+lat leads) [septal enlargement]
  • AF, WPW syndrome, ventricle ectopics, VT
• Echo;
  
  • Asymmetrical septal hypertophy
  • Small LV cavity with hypercontractile post wall
  • Midsystolic closure of aortic valve
  • Systolic ant movement of mitril valve

Question 4

What is restrictive cardiomyopathy?

Outline the;

• Causes
• Signs & symptoms
• Diagnosis

Answer 4

Myocardium becomes rigid restricting stretch and filling.

Causes;

• Idiopathic
• Amyloidosis, haemochromatosis, sarcoidosis, scleroderma, Loffler’s oesinophilic endocarditis, endomyocardial fibrosis

Signs & symptoms;

• Like constrictive pericarditis
• Features of RVF predominate; Inc JVP, x & y descents, hepatomegaly, oedema, ascites

Diagnosis;

• Cardiac catheterization

Question 5

What is cardiac myxoma?

Outline the;

• Causes

Answer 5

Rare benign cardiac tumoiur.

Causes;

• Usually sporadic, may be familial