Cardiomyopathy Flashcards
Cardiomyopathy definition
Heart muscle disorder
Cardiomyopathy types
Dilated
Hypertrophic
Restrictive
Arrhythmogenic right ventricular cardiomyopathy (ARVC)
Cardiomyopathy epidemiology
Can occur at younger age
Suspect if presenting with CCF
Hypertrophic = most common cause of unexpected death in childhood
Often genetic component
Cardiomyopathy causes
Connective tissue disorders
Endocrine - diabetes, thyroid
Drugs - chemo, cocaine, alcohol
Infection
Nutrition - obesity, vit B1, Ca, Mg deficiencies
Genetic - duchenne muscular dystrophy
Dilated cardiomyopathy (DCM) epidemiology
Most common type
Enlarged ventricular size, with normal ventricular wall thickness and systolic dysfunction
Left or both ventricles
Most common indication for heart transplant
Men and Africans and genetic link
DCM causes
Ischaemic heart disease
Alcohol
Cocaine
Thyroid
Valvular disease
Genetic
Idiopathic
Infection - bacterial, HIV, coxackie virus, viral myocarditis
Autoimmune
CT disorder
Granulomatous disorder
Drug
Peripartum in pregnancy -poor prognosis
DCM pathophysiology
Damage to myocardium
Necrosis of myocardial cells
Chronic fibrosis
Remaining tissue dilates and hypertrophies to compensate
Link with mitral/tricuspid regurgitation
Can lead to AF, thrombus formation
DCM presentation
SOB
Fatigue
Peripheral oedema
Raised JVP
Loud S3 and S4
Arrythmia
Thromboembolism
Acute myocarditis
Heart failure
DCM ECG
Sinus tachycardia
T wave inversion
Pathological Q waves
ST depression
LBBB
DCM investigations
ECG
CXR
Echo
Coronary angiogram if ischaemic heart disease suspected
Cardiac muscle biopsy if specific cause suspected
DCM CXR
Enlarged heart
Signs of heart failure
Pleural effusion
DCM echo
Dilated hypokinetic chambers
Rule out valve disorders
Check for thrombus
DCM management
Tx for reversible causes
Prophylactic anticoagulation
Treat arrhythmia
Consider pacemaker if block /ICD for arrhythmia
Treat as for heart failure
- ACEi/ARB
- +/- Beta blocker
- Diuretics - loop and thiazide, spironolactone
- Nitrates
Consider heart transplant
DCM prognosis
70% mortality within 5 years
Worse if:
Ventricular wall is thin
Ventricles markedly dilated
Hypertrophic cardiomyopathy (HCM) definition
Autosomal dominant genetic disorder that causes diastolic dysfunction, with or without outflow obstruction
Can cause sudden cardiac death in young athletes
LV hypertrophy - LV outflow obstruction, mitral valve problems, myocardial ischaemia and tachyarrhythmias
HCM causes
Autosomal dominant - variable penetrance and expressivity
Mutation in one+ of 12 genes that code for cardiac proteins - esp troponin T mutations
HCM pathophysiology
Genetic defect in codes for cardiac proteins (beta-myosin heavy chain, troponin, alpha-tropomyosin)
Disorganised cardiac matrix
LV hypertrophy, esp in ant ventricular septum
HCM presentation
Asymptomatic
SOB
Chest pain
Syncope on exercise/alcohol
Palpitations
Sudden death, esp if experiencing syncope, due to outflow tract obstruction or arrhythmia
FH
Aortic stenosis / coronary artery disease
HCM examination
Forceful apex beat
Late ejection systolic murmur
- reduced when squatting
Prominent JVP
Abnormal BP response to exercise - no rise in BP
AF
HCM investigations
ECG
Echo - standard diagnostic test
CXR
Cardiac MRI
Myocardial biopsy
Cardiac catherisation
HCM ECG
ST changes
T wave inversion
LVH
AF
HCM echo
Asymmetric septal hypertrophy > 15mm
Ratio of septal wall to posterior wall > 1.4:1
Non-dilated left ventricular cavity
Normal systolic function
Absence of valvular disease
HCM management
Beta blockers
Verapamil
Reduce cardiac contractibility - dilate LV
Beware of ACEi, ARB, nitrites, diuretics
Reduce preload - decrease chamber size - exacerbate symptoms
ICD
Avoid sports or strenuous exercise
Surgical myectomy
Heart transplant
Risk factors for sudden cardiac death
Unexplained syncopal events
Episodes of VF or VT
Abnormal BP response to exercise
FH
Age < 30
Restrictive cardiomyopathy definition
Reduced compliance of ventricular walls during diastolic filling
Type 1 - infiltration of myocardium by invasive substance (amyloid plaques, sarcoidosis, iron in haemochromatosis)
Type 2 - fibrotic myocardium
Leads to high diastolic filling pressures and so pulmonary hypertension
Associated with mural thrombi
RCM aetiology
Idiopathic
Lofflers syndrome - tropical disease
Amyloidosis
Sarcoidosis
Haemochromatosis
RCM presentation
CCF signs
Heart size enlarged
RVF signs - raised JVP, hepatomegaly, oedema, ascites
AF and other arrhythmias
Similar to constrictive pericarditis symptoms
RCM ecg
Non-specific T and ST changes
Pathological Q waves
LVH
RCM CXR
Heart size normal or small
RCM echo
Normal systole
Dilated atria
Myocardial hypertrophy
Differentiate from restrictive pericarditis - thickened pericardium
RCM medications not to give
Diuretics - reduce preload
Digoxin - sensitivity in amyloidosis pts
Nitrites - reduce after load - hypotension
RCM management
Tx underlying cause
Endocardial resection
Heart transplant
Cardiomyopathy differentials
Ischaemic heart disease
Valvular heart disease - esp mitral and aortic
Athletes
Pericarditis
Pulmonary stenosis
VSD
