cardiomyopathy Flashcards
Define cardiomyopathy?
A group of diseases in which the myocardium becomes structurally and functionally abnormal
- In the absence of coronary artery disease, valvular disease and congenital heart disease
- It can affect young people
what is the difference between primary and secondary cardiomyopathy?
primary- confined to myocardium
secondary- part of systemic disease
what are the 3 types of cardiomyopathy>
Dilated – ventricle dilated, thin walls, reduced ventricular pressure
Hypertrophic – muscle hypertrophies inwards, more rigid, obstruction etc.
Restrictive – basically the same amount of muscle but it’s rigid and doesn’t pump as well as normal
describe the history for cardiomyopathy
Symptoms of HF:
- SOB on exertion
- Fainting
- Fatigue
Sudden death often 1st presentation
Family history
what is seen on examination in cardiomyopathy?
- Respiratory crackles
- Murmurs
- S3, S4
outline the investigations for cardiomyopathy?
No single diagnostic test for all types
ECHO
Can also do bloods, BNP, CXR, ECG, cardiac catheterisation, stress test
outline the pathophysiology of dilated cardiomyopathy?
Ventricles enlarge and become dilated.
Walls thin and weaken -> can’t contract effectively.
Think of the Law of Laplace: increased radius leads to reduced ventricular pressure
what are the risk factors for dilated cardiomyopathy?
Alcohol, post-viral, haemochromatosis, genetic
outline the presentation of dilated cardiomyopathy?
Signs and symptoms of HF
Displaced apex beat, TR/MR murmur, S3
what are the investigations for dilated cardiomyopathy?
Globular heart on CXR, dilated ventricle on Echo
outline the pathophysiology of hypertrophic cardiomyopathy?
- H for Hench – muscle thickens inwards.
- Increased stiffness of the muscle affects pumping.
- Thickened muscle disrupts electrical conduction and causes arrythmia.
- Hypertrophic Obstructive Cardiomyopathy (HOCM) = thickened ventricle obstructs the outflow of blood.
- 50% is familial (autosomal dominant)
what are the symptoms of hypertrophic cardiomyopathy?
Usually asymptomatic
Sudden cardiac death is often the 1stpresentation
Angina, dyspnoea on exertion, palpitations, syncope
what are the signs of hypertrophic cardiomyopathy?
Ejection systolic murmur
Jerky carotid pulse
Double apex beat but NOT DISPLACED
S4
LVH by voltage criteria
- Deep S in V1/2
- Tall R in V5/6
- S in V1 + R in V5 or V6 ≥ 7 large squares
what are the investigations for hypertrophic cardiomyopathy?
ECG: Q waves, left axis deviation, signs of left ventricular hypertrophy
Echo: ventricular hypertrophy (asymmetrical septal hypertrophy
Outline the pathophysiology of restrictive cardiomyopathy?
R for Rigid – ventricles become abnormally rigid and lose flexibility.
Impaired ventricular filling during diastole.
Reduced preload -> reduced blood flow + backing up of blood.
