Cardiomyopathy Flashcards
Define cardiomyopathy
Group of diseases that affect the myocardium
Leading to impaired cardiac function
What are the mains types of cardiomyopathy?
Hypertrophic cardiomyopathy
Dilated cardiomyopathy
Restrictive cardiomyopathy
Arrhythmogenic RV cardiomyopathy
Define hypertrophic cardiomyopathy?
Left ventricle / septum hypertrophy
Often without an obvious cause
Leads to diastolic dysfunction and arrhythmias.
Leading cause of sudden cardiac deaths in young athletes.
What is the key idea of dilated cardiomyopathy?
Dilation and impaired contraction of one or both of the ventricles - reduced ejection fractions.
Ventricular wall fraction may be reduced or normal.
Fibrosis of chamber walls
Dilation cam impair valve function - particularly mitral and tricuspid.
Result in systolic heart failure
What is the key idea of restrictive cardiomyopathy?
Rigid ventricular walls (thickened) - unable to relax after filling = limit filling = poor diastolic function
Reduced cardiac output despite normal contractile function.
Ventricle size is normal although typically bilateral atrial dilation.
Biospy - non-specific interstitial myocardial fibrosis.
What is the main danger of hypertrophic cardiomyopathy?
Sudden cardiac death in young people
Peak incidence between 20-30yrs - particularly in elite athletes.
What are the symptoms of hypertrophic cardiomyopathy?
May be asymptomatic - particularly if low cardiac output demands
May develop HF, angina, syncope or sudden cardiac death. palpitations.
What is the basic physiology of hypertrophic cardiomyopathy?
Thicked septum/LV wall
Diastolic dysfunction - reduced EDV
LV outflow tract obstruction - reduced ejection fraction
Reduced cardiac output
What is the typical management of hypertrophic cardiomyopathy?
Familial screening
Beta blockers and calcium channel blockers for symptomatic relief
Septal reduction therapies - septal myectomy or alcohol septal ablation
Implantable cardioverter defibs - for prevention of sudden cardiac death
What is the typical cause of hypertrophic cardiomyopathy?
Familial
Typically an autosomal dominant mutation in sarcomere proteins - often associated with Wolf-Parkinson-White syndrome and Friedreichs ataxia.
What is the most common cause of dilated cardiomyopathy?
Primary - genetic (50% of cases are AD), may be x-linked associated with dystrophen protein.
Seconday - Coaxacie B virus, alcohol/cocaine abuse, coronary artery disease/ischemic cardiomyopathy, valvular disease, arrythmia, MI, myocarditis
What are the common signs and symptoms of dilated cardiomyopathy?
Symptoms of HF - dyspnoea, PND, orthopnoea
S3 gallop - large amount of blood hitting a very compliant left ventricle
Often feel tired, chest pain, SOB, swelling of feet, abdomen and potential pulmonary oedema, palpitations.
What is the common management of dilated cardiomyopathy?
Heart failure therapy
Fluid restriction
Diuretics - spironolactone.
Daily weights
ACE inhibitors
Beta blockers
ICD
Heart transplant
What is the most common cardiomyopathy?
Dilated cardiomyopathy.
What are the main arrythmias that DCM can cause?
Atrial fibrillation
Ventricular tachycardias
Heart block
What device therapies can be used in cardiomyopathy?
ICD - prevent sudden cardiac death in high risk patients
LVAD - in advanced cases - help maintain cardio output.
What are the common clinical presentations fo cardiomyopathy?
Heart Failure
Sudden death
Atrial fibrillation
Stroke
What is the basic physiology of arrhythmogenic cardiomyopathy?
Autosomal dominant (variable penetrance) - desmosomal proteins at the intercalated disks such as Plakophilin 2 - problems with cell to cell adhesions.
Predominant right sides failure and arrhythmia.
RV walls is severely thinned with myocyte loss, replaced by fatty and fibrosis infiltration.
Effects the electrical circuitry of the heart - leading to rhythmic abnormalities - associated with lightheadedness and dizziness.
Death occurs secondary to progressive CHF or fatal arryhtmias.
What are some indicative signs and symptoms of arrhythmogenic cardiomyopathy?
Classical cardiomyopathy/heart failure symptoms plus.
Onset age 20-30yrs
Myocarditis - repeated with no other identified cause
Palmoplantar keratoderma (itchy,cracked or flaky skin on plans and soles) and tightly cured, brittle hair or detail changes - as protein affected in heart is also found in these areas.
What are the key signs/symptoms of any cardiomyopathy?
Signs of heart failure
Genetic history
Arrythmias - A.fib, SVT, Vtachy
Sudden cardiac death - particularly in young adults
Exercise induced chest pain, syncope, palpitations
What investigations should be done for suspected cardiomyopathy?
Bedside - FH, cardiovascular exam, ECG, obs,
Blood - FBC, LFT, U&Es, CRP, troponin, BNP.
Imaging - echocardiogram, Cardiac MRI, CXR
Other -24hr ECG, exercise stress test, cardiac biospy
What are some common causes of restrictive cardiomyopathy?
Amyloidosis - EC accumulation of protein fibrils, form insoluble beta pleated sheets
Sarcoidosis - granuloma development
Radiaton-induced fibrosis
Endomyocardial fibrosis - African children and young adults - nut defieicny and parastitic infection
