cardiomyopathy Flashcards
definition of cardiomyopathy
Primary disease of the myocardium. Cardiomyopathy may be dilated, hy-pertrophic or restrictive.
dilated - a dilated flabby heart of unknown cause
hypertrophic - LV outflow tract obstruction from asymmetric septal hypertrophy
main cause of cardiomyopathy
idiopathic
cause of dilated cardiomyopathy
- Post-viral myocarditis,
- alcohol,
- HTN
- drugs (e.g. doxorubicin, cocaine),
- chemo,
- familial (25% of idiopathic cases, usually autosomal dominant),
- thyrotoxicosis,
- haemochromatosis,
- peri- or postpartum,
- autoimmune
causes of hypertrophic cardiomyopathy
Up to 50% of cases are genetic (autosomal dominant)
with mutations in b-myosin, troponin T or a-tropomyosin (components of the contractile apparatus).
causes of restrictive cardiomyopathy
Amyloidosis,
sarcoidosis,
haemochromatosis,
scleroderma,
Loffler’s eosinophilic endocarditis,
endomyocardial fibrosis
epidemiology of cardiomyopathy
Prevalence of dilated cardiomyopathy and hypertrophic cardiomyopathy: 0.05–0.20%.
Restrictive cardiomyopathy - rare.
sx of dilated cardiomyopathy
- symptoms of HF
- arrhythmia
- thrmoboembolism
- FH of sudden death
- fatigue
- dyspnoea
- pul oedema
- RVF
sx of hypertrophic cardiomyopathy
- asymptomatic
- syncope
- angina
- dyspnoea
- palpitation
- CCF
- arrhythmia
- FH sudden death
sx of restrictive cardiomyopathy
dyspnoea
fatigue
arrhythmias
ankle or abdo swelling
FH sudden death
signs of dilated cardiomyopathy
- raised JVP
- displaced and diffuse apex beat
- functional mitral and tricuspid regurg
- 3rd heart sounds, gallop
- raised pulse
- low BP
- pleural effusion
- oedema
- jaundice
- hepatomegaly
- ascites
signs of hypertrophic cardiomyopathy
jerky carotid pulse
a wave in JVP
double apex beat
ejection systolic murmur
systolic thrill at lower L sternal edge
signs of restrictive cardiomyopathy
similar to constrictive pericarditis
raised JVP (Kussmaul’s sign - further raised on inspiration), prominent X and Y descents
palpable apex beat
3rd heart sound
ascites
ankle oedema
hepatomegaly
Ix for cardiomyopathy
CXR
ECG
echo
Cardiac catheterization: May be necessary for measurement of pressures.
Endomyocardial biopsy: May be helpful in restrictive cardiomyopathy.
Pedigree or genetic analysis: Rarely necessary.
CXR for cardiomyopathy
cardiomegaly
signs of HF
ECG for cardiomyopathy
non-specific ST changes
conduction defects , arrhythmias
hypertrophic:
- LAD
- LVH
- Q waves in inferior and lateral leads
resrictive = low voltage complexes
echo for cardiomyopathy
dilated - Dilated ventricles with ‘global’ hypokinesia.
hypertrophic - Ventricular hypertrophy (disproportionate septal involvement)
restrictive
- non-dilated non-hypertrophied ventricles
- atrial enlargement
- preserved systolic function
- diastolic dysfunction
- granular or ‘sparkling’ appearance of myocardium in amyloidosis.
Ix results for dilated cardiomyopathy
blood
- BNP
- reduced Na = poor prognosis
CXR
- cardiomegaly
- pul oedema
ECG
- tachycardia
- non-specific T wave changes
- poor R wave progression
echo
- globally dilated hypokinetic heart and low ejection fraction
- look for MR, TR, LV mural thrombus
hypertrophic cardiomyopathy Ix results
ECG
- LVH
- progressive T wave inversion
- deep Q waves (inferior and lateral leads)
- AF
- WPW syndrome
- ventricular ectopics
- VT
echo
- asymmetrical septal hypertrophy
- small LV hypertrophy with hypercontractile posterior wall
- midsystolic closure of aortic valve
- systolic anterior movement of mitral valve
MRI
cardiac catheterisation
- helps assess: severity of gradient, coronary artery disease, mitral regurg
- may provoke VT
electrophysiological studies may be needed
exercise test +- Holter test to risk stratify
