Download Cardiomyopathy

Cardiomyopathy
Disorder of heart muscle
1. Idiopathic Congestive (Dilated) Cardiomyopathy
(Increased ventricle size, decreased contractility)
Prevalence: 0.2%
Mortality: 40% in 2yrs (sudden death, cardiogenic shock)
Typical Patient
 Young man
 RVF
 LVF
 Cardiomegaly
 AF
 +/- emboli
Exclude
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Ischaemia,
Valvular disease,
High BP
Pericardial disease
Specific heart muscle diseases
Echocardiography - globally hypokinetic, dilated heart
Other tests: no or non-specific abnormalities
Management: as for heart failure. Consider transplant.
2. Hypertrophic (Obstructive) Cardiomyopathy
Hypertrophy of ventricular muscle of no known cause.
Leads to:
 Gradually falling LV function
 Sudden death
Risk increased by:
 Hard exercise
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Anaesthesia
Family history of sudden death
Paroxysmal AF
Ventricular tachycardia
Prevalence: 0.2%
Associations
25% associated with subaortic obstruction and/or systolic anterior motion of mitral valve
70% associated with gene mutations
Inheritance: Autosomal dominant (50% are sporadic)
Screening relatives: Helpful preventative measures, but life insurance problems
Symptoms
 Often no
 Dyspnoea (PND)
 Exertional or atypical chest pain
 Faints (15-25%, due to arrhythmias)
 Palpitations
 Features of right heart failure
Signs
Often none
Jerky pulse (rapid upstroke)
Double impulse at apex
S3
S4
Late systolic murmur (outflow tract obstruction +/- mitral regurge)
AF (in ~5%)
ECG: LVH, LBBB
Echocardiography:
Usually diagnostic
Asymmetrical septal hypertrophy
Systolic anterior movement of mitral valve
Midsystolic closure of aortic valve
Cardiac Catheterisation:
Small banana-like LV cavity
Thickened papillary muscles and trabeculae
Cavity obliteration in systole
Management
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ß-blockers or Verapamil for chest pain
Amiodarone for arrhythmias
Try to maintain sinus rhythm
Dual chamber pacing - in outflow obstruction
Consider septal myomectomy
Paroxysmal AF - anticoagulate
3. Restrictive Cardiomyopathy
Endomyocardial stiffening
Signs as in Constrictive Pericarditis
Commonest in the Tropics (due to Idiopathic fibrosis)
In UK commonest cause - Amyloidosis
Differential Diagnosis - specific muscle diseases
Amyloid and Carcinoid may be restrictive (e.g. Amyloid and cardiac involvement in
Friedreich's ataxia - may resemble HOCM)
Chief causes - Ischaemia, Hypertension, Infection (Rheumatic fever, Infective
Endocarditis, Tuberculosis, Lyme disease), Alcohol, Cocaine, Ecstasy, Post-partum,
smoking, connective tissue diseases, diabetes, hyper- or hypothyroidism, Acromegaly,
Addison's disease, Phaeochromocytoma, Haemochromatosis, Sarcoid, Duchenne
Muscular Dystrophy, myotonic dystrophy, irradiation, cytotoxics, storage diseases.
ACUTE MYOCARDITIS
Inflammation of the myocardium
May present similarly to MI
Causes:
Viral
 Coxsackie
 Lyme disease
 Diptheria
 Other infections
 Rheumatic fever
 Drugs
The Patient:
 Faints
 Rapid pulse
 Angina
 Dyspnoea
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Arrhythmia
Heart Failure
Tests:
 Exclude MI and pericardial effusion
 Consider viral or Chagas' serology
Management:
 Supportive
 May recover spontaneously or may develop intractable heart failure