Cardiomyopathy Flashcards
What is cardiomyopathy a result of?
Heart disease resulting from a primary abnormality in the myocardium - primary abnormalities are of the vasculature and valves, not the myocardium
What are the 3 patterns of cardiomyopathy?
i. Dilated Cardiomyopathy
ii. HypertrophicCardiomyopathy
iii. Restrictive Cardiomyopathy
What is the most common cardiomyopathy?
Dilated Cardiomyopathy
What is dilated cardiomyopathy?
It is contractile (systolic) dysfunction that results in 4 chamber dilatation resulting in a heart that is 2-3x normal weight.
What are the 5 major etiologies of dilated cardiomyopathy?
- Post myocarditis
- Alcohol
- Peripartum cardiomyopathy
- Genetic
- Doxorubicin and Daunarubicin therapy
*6. Idiopathic
What do genetic abnormalities that lead to cardiomyopathy normally affect?
Genetic abnormalities most commonly affect the cytoskeleton
How can iron overload cause dilated cardiomyopathy?
Iron accumulates within myocytes and interferes with metal-dependent enzyme systems
What is the treatment for dilated cardiomyopathy?
Medical management of systolic heart failure and heart transplantation may be the option for patients whose
symptoms are recalcitrant to optimal medical therapy and who are appropriate candidates
What are the other names for hypertrophic cardiomyopathy?
“Idiopathic hypertrophic subaortic stenosis”
“Hypertrophic obstructive cardiomyopathy”
What is the cause of hypertrophic cardiomyopathy?
Caused by missense mutation in 1 of at least 12 genes encoding cardiac sarcomere proteins that leads to greater septum hypertrophy causing abnormal diastolic filling with marked LV hypertrophy
What is the shape of the LV in hypertrophic cardiomyopathy?
Banana shaped
What are the histologic features of hypertrophic cardiomyopathy?
Myocytes are haphazard and disorganized as well as hypertrophied
What is the type of heart failure found in dilated heart failure?
Systolic
What is the type of heart failure found in hypertrophic cardiomyopathy?
Diastolic
What are some of the clinical features of hypertrophic cardiomyopathy?
Dyspnea Harsh systolic murmur Anginal pain Intractable heart failure Arrhythmia
What is the most common cause of sudden death in young athletes?
Hypertrophic cardiomyopathy
What are the treatments for hypertrophic cardiomyopathy?
- Medical therapy aimed at enhancing ventricular relaxation so that diastolic filling is enhanced
- Surgical septal excision
What is restrictive cardiomyopathy?
Primary decrease in ventricular compliance, resulting in impaired ventricular filling during diastole. Systolic function is unaffected
What are some of the possible causes restrictive cardiomyopathy?
Radiation fibrosis
Amyloidosis
Sarcoidosis
What are the size changes of the heart in restrictive cardiomyopathy?
There generally are none as the LV is often normal in size
What is amyloidosis and how does it lead to restrictive cardiomyopathy?
Results from pathologic proteinaceous substance that is due to misfolding that is deposited in the myocardial interstitium that leads to impeded LV filling due to stiffness although it is normal in size
What are the histological and molecular features of amyloidosis?
They have a congo-red stain with an apple-green birefringence under polarized light.
They are often ß-pleated sheet