Restrictive Cardiomyopathy

Question 1

What is Restrictive Cardiomyopathy?

Answer 1

Restrictive cardiomyopathy is where fibrosis or infiltration into the myo/endocardium causes them to be stiff and have reduced ventricular compliance.

This means that ventricles don’t fill well during diastole.

This causes the artria to become enlarged.

Question 2

What are the causes of Restrictive Cardiomyopathy? (7)

Answer 2

Primary:
1.Loeffler’s endocarditis - eosinophils

Fibrotic:
2. Radiation
3. Endimycocardial fibrosis and endocardial fibroelastosis (children)

Infiltrative:
4. Amyloidosis
5. Sarcoidosis
6. Haemochromatosis
7. Scleroderma

Question 3

What are the causes of Loeffler’s endocarditis?

Answer 3

Raised eosinophils e.g.

• Allergy
• Parasite
• Drug reaction
• Leukaemia

Question 4

What are the clinical features of Restrictive Cardiomyopathy? (6)

Answer 4

Dilation of the atria can cause:
1. Widening of the valves causing MR and TR
2. Re-entry pathways causing AF (clots and stroke)

Reduced cardiac output can cause
2. Right heart failure - raised JVP, hepatomegaly, pedal oedema
4. Left heart failure - breathlessness, orthopnia, PND
5. Reduced cardiac perfusion -> VT/VF -> Sudden cardiac death (rarer than in HOCM)

Fibrosis of the endocardium (epithelium) is one of Virchow’s triads ->
6. clots

Question 5

What are the investifations for Restrictive Cardiomyopathy? (6)

Answer 5

1. CXR - oedema
2. ECG: AF, bundle branch block (fibrosis), reduced QRS amplitude
3. ECHO: bialteral atrial dilation +/- thickening, reduced ventricular relaxation
4. Cardiac catheterisation - square root sign
5. MRI/CT
6. Biopsy

Question 6

How is Restrictive Cardiomyopathy managed? (4)

Answer 6

1. Reduce preload e.g. reduce fluid volume with reduced fluids, salt and diuretics
2. ACE-i
3. Anticoagulation
4. Treat the underlying cause