Lec 9 Cardiomyopathy Pathology Flashcards
What is a cardiomyopathy?
structural or functional abnormality of myocardium independent of other valvular/coronary/myocardial involvement in systemic disease
What are 3 types of cardiomyopathy?
- dilated
- hypertrophic
- restrictive
What is most common type of cardiomyopathy?
dilated
Who gets dilated cardiomyopathy [DCM]?
- may occur at any age
- most common males 20-50
- often idiopathic or congenital
What are findings of dilated cardiomyopathy?
- left ventricular dilation
- systolic dysfunction [EF < 50%]
- S3
- heart failure
- dilated heart on echo
- balloon appearance of heart on CXR
What are causes of dilated cardiomyopathy?
- idiopathic or congenital
- ABCCCD
- – Alcohol abuse
- – wet bebriberi [thiamine deficiency]
- – coxsackie B virus myocarditis
- – chronic cocaine use
- – chagas disease
- – doxorubicin toxicity
- hemochromatosis
- peripartum cardiomyopathy
What is major genetic cause of dilated cardiomyopathy?
mutation in TTN gene that encodes titin
autosomal dominant
What are pathological findings of dilated cardiomyopathy?
- enlarged globular heart [2-3x normal weight]
- 4 chamber dilation + hypertrophy
- thin flabby walls
- annular dilation of atrial-ventricular valves
- eccentric hypertrophy
What are histo features of dilated cardiomyopathy?
- hypertrophied myocytes
- boxcar nuclei
- some myocytes stretched and irregular
- interstitial fibrosis
What are major infectious causes of dilated cardiomyopathy?
viral myocarditis: coxsackie B, adenovirus
parasite: T. cruzi = chagas disease
What are some toxins that can cause dilated cardiomyopathy?
alcohol or cocaine use
What are mechs of alcoholic dilated cardiomyopathy?
- direct toxic affect of alcoholic
- secondary nutritional thiamine deficiency
- alcohol additives
Who gets dilated cardiomyopathy from alcohol?
men 30-55 with > 10 yrs of alcohol consumption
If sudden cardiac death in young athlete what should you think?
hypertrophic cardiomyopathy
Who gets hypertrophic cardiomyopathy?
100% familial/genetic
males > females
young atheletes
What happens in hypertrophic cardiomyopathy?
left ventricle hypertrophy
diastolic dysfunction = can’t fill the heart
What is genetics of hypertrophic cardiomyopathy?
mutation in sarcomere protein for myosin heavy chain
autosomal dominant
What are path findings of hypertrophic cardiomyopathy?
hypertrophy of myocardium
- asymmetrical hypertrophy beflow aortic valve in most pts
- greater hypertrophy of interventricular septum than free LV wall
- aberrant myofibers in conduction system –> fatal arrhythmia + sudden death
What is most common cause of restrictive cardiomyopathy?
amyloidosis
What are path findings of restrictive cardiomyopathy?
- ventricles normal or slightly enlarged
- myocardium firm and normal thickness
- bi-atrial dilation because poor ventricular filling and pressure overloads
- patchy areas of fibrosis
What is arythmogenic right ventricular cardiomyopathy [ARVC]?
inherited cardiomypathy
- causes RV failure and rhythm disturbances [ventricular fibrillation or tachycardia]
- fatty and fibrous tissue replace heart muscle
- can lead to suddne death
- usually in young people
- autosomal dom mut in desmosomal protein
What is isolated left ventricular noncompaction [LVNC]?
congentical myocardial disorder causes CM in children
persistence of noncompacted endocardial layer charactersisc of early fetal period
LV dilated or hypertrophied
sponge-like appearance of LV wall
If you see eosinophils in cardiomyopathy what should you think?
hypersensitiviy
parasites [Chagas]
If you see lymphocytes in cardiomyopathy what should you think?
viral
