Cardiomyopathy, Myocarditis, Pericardial Disease Flashcards
What is cardiomyopathy and what are the 3 types of cardiomyopathy?
Primary abnormality of the myocardium
- cardiac dysfunction not attributable to the pressure or volume overload
- primary disease of myocardium
- dilated cardiomyopathy
- hypertrophic cardiomyopathy
- restrictive cardiomyopathy
What is dilated cardiomyopathy? What do you see on a trichrome stain?
- most common
- contractile (systolic) dysfunction
- four chamber dilation
- 2-3 X normal weight
Trichrome stain:
myocyte hypertrophy and interstitial fibrosis
What are non-genetic causes of dilated cardiomyopathy?
- myocarditis
- peri partum
- toxic (e.g. alcohol)
- idiopathic
What are genetic causes of dilated cardiomyopathy?
cytoskeleton or mitochondria
–>defect in force generation, force transmission and or myocyte signaling
What does dilated cardiomyopathy lead to? How do you treat it?
progressive systolic congestive heart
- heart failure symptoms
- arrhythmias
- mural thrombi with embolic complications
Treat:
Medical therapy
Heart transplant
What is hypertrophic cardiomyopathy? What does it lead to?
Idiopathic hypertrophic subaortic stenosis (IHSS)
Hypertrophic obstructive cardiomyopathy (HOCM)
1. marked LV myocardial hypertrophy
-septum>free wall hypertrophied –>banana shaped LV cavity
Leads to:
- abnormal diastolic filling
- left ventricular outflow obstruction
- septal hypertrophy
- anterior mitral valve leaflet contacts ventricular septum
What does hypertrophic cardiomyopathy look like histologically?
hypertrophied myocytes
haphazard pattern
interstitial fibrosis
What are the causes of hypertrophic cardiomyopathy?
100% genetic causes
- autosomal dominant
- variable expression
- mutation in genes that encode proteins of sarcomeres
What are some outcomes to hypertrophic cardiomyopathy? What are the treatments?
- diastolic heart failure
- exertional dyspnea
- harsh systolic ejection murmur
- anginal pain
- intractable heart failure
- arrhythmias-some have defib put in becuase can go into fatal arrhythmias
- SUDDEN DEATH IN YOUNG ATHLETES
Treatments:
Medical therapy enhancing ventricular relaxation
Surgical excision of muscle
What is restrictive cardiomyopathy?
primary decrease in ventricular compliance
- firm/stiff myocardium
- ability to expand markedly limited
- impeded left ventricular filling during diastole
- systolic function preserved
- LV cavity size normal
What could cause restrictive cardiomyopathy?
idiopathic, radiation fibrosis, amyloidosis (amyloid build up), sarcoidosis (granulomas), inborn errors of metabolism, endocardial fibroelastosis, loeffler endomyocarditis (eosinophilia)
What is an amyloid?
misfolded proteins deposits in extracellular space causes tissue damage multiple proteins can deposit as amyloid Common features: 1. beta pleated sheet configuraion 2. congo red staining in tissue -apple green under polarized light
What is myocarditis?
inflammatory process resulting in myocardial injury
What are infectious ways of getting myocarditis?
Viruses
- Enterovirus- Coxsackie A and B
- most common etiology in US*** - cytomegalovirus
- HIV
Bacteria
- Diphtheria
- Borrelia burgdorferi-Lyme disease
Parasites
- Trypanosoma cruzi (Chaga’s disease)
- endemic in areas of south africa - trichinosis
- toxoplasmosis
What are noninfectious ways of getting myocarditis?
Immune mediated
- Hypersensitivity reactions
- drugs - Rheumatic fever
- Giant cell myocarditis
- sarcoidosis
