Cardiomyopathy and anti-arrythmatic Flashcards
What are the features of the heart in dilated cardiomyopathy?
progressive cardiac dilation
systolic dysfunction
hypertrophy
enlarged, heavy flabby heart
What are common causes of dilated cardiomyopathy?
ischemia valvular HTN idiopathic familial inflammmatory-infectious toxic metabolic nutritional neuromusc
What percentage of dilated myopaties are indicated by genetic casues?
20-50% majority autosomal dominant mutations encoding cytoskeleton proteins
What viruses have been linked to dilated cardiomyopathy?
coxasckie B or echovirus, self limited in young ppl
unclear mecchanism
What two ways can alcohol cause dilated cardiomyopathy?
alcohol: direct toxic effect myocardium
alcohol: indirect toxic effect associated with thiamine disease (beriberi disease0
What chemotherapy drug can lead to dilated cardiomyopathy
doxorubicin as well as other anthracyclines, which is dose dependent
What is the dilated cardiomyopathy due to pregnancy?
peripartum cardiomyopathy; late in pregnancy or several weeks to months posptartum; probable cause HTN volume overload nutritional def prolactin
What is the dilated cardiomyopathy gross morphology?
four chamber dilation variable thickness mural thrombi valves are normal, but may have tricuspid or mtiral regurg cardiomegaly
What is the histology associated with dialted cardiomyopathy?
myocyte hypertrophy
interstital & endocardial fibrosis; no necrsois
not specific for DCM unless iron overload is cause adn iron present
What puts you at increased risk for idiopathic dilated cardiomyopathy
black
male
HTN
chronic Beta-agonist; relatively rare
How does idiopathic dilated cardiomyopathy usually present?
heart failure symtpoms
or anginal chest pain
occasionally sudden death
What are the treatmments for dilated cardiomyopahty?
ACE inhibitor, other diuretics potassium/magnesium beta blocker digoxin in face of persistnent syndromes wafarin-with thrombus/afib ICD- MI oruncontrolled vT
What is the definition of arrhythmogenic right ventricular cardiomyopathy?
inherited disease of cardiac muscle
right ventricle failure and various rythm disturbance
sudden death possible
–right ventricle is severely thinned bc of loss of myocytes with extensive fatty infiltration and fibrosis—
What is the inheritance of arrhythmogenic right ventricular cardiomyopathy?
autosomal dominant
Where is the defect in arrhythmogenic right ventricular cardiomyopahty?
defective cell adhesion proteins in desmosomes that link adjacent cardiac myocytes
What is the clinical syndrome associated with arrhythmogenic right ventricular cardiomyopathy?
young adults
arrhythmia (VTach)
sudden death
right ventricular failure
What is the morphology of arrhythmogenic right ventricular cardio?
thin & dilated right ventricular wall with fatty infiltration (essential feature) and intersitial fibrosis
What is hypertrophic cardiomyopathy?
myocardial hypertrophy, with abnormal diastolic filling, poorly complian
heart is thick-walled, heavy and hypercontracting
priimarily diastolic dysfunction, systolic functio usually perserved
ventricular outflow obstruction
What is the gross morphology of HCM
massive myocardial hypertrophy, frequent disporportionate thickening of septum
endocardial thickening and mural plaques in outflow tract
What is the histology of HCM?
marked hypertrophy
intersitial fibrosis
myofiber disarray
intersitial fibrosis
What are the mutations associated with HCM?
increase myofilament activation resutling in myocyte cotnractility
missesnse in sarcomeric proteins
myosin heavy chain
myosin binding protein
cardiac TnT
DEFECTS IN DIRECT SARCOMERE FUNCTION
DEFECT IN TRANSFER OF ENERGY TO SARCOMERE
What is the genetic inheritance of HCM?
prognosis correlated with mutation
familiail, AD, Variable expression
one of the most common causes of sudden unexplained death in athletes
What are the arrythmias associated with HCM?
paroxysmal supraventricular arrthmias
Afib
Non-sustained ventricular tachy
sustained ventricular tachy/ventricular fibrillation
What are the clinical features of HCM?
presentation after puberty
asymptomatic frequently
sudden death in young athletes
syncope due to left ventricular outflow obstruction
Tx: surgical excision, ventricular relaxing drugs
What are the risk facctors for cardiac death in HCM?
marked ventricular hypertrophy young age hypotension on excercise syncope hx of aborted cardiac rest FHx of sudden cardiac death certain geneti mutations