Cardiomyopathy Flashcards
What is cardiomyopathy?
Diseases that primarily involve the MYOCARDIUM and cause MYOCARDIAL DYSFUNCTION
What is the most common cardiomyopathy?
Dilated
What is the most common known cause of dilated cardiomyopathy?
Myocarditis
Besides myocarditis, what are other common causes of dilated cardiomyopathy?
- Alcohol- direct toxic effect
- Thiamine def–> dec in ATP
- Drugs- doxorubicin, daunorubicin, cocaine
- Post partum
- Organic solvents
- Acromegaly, myedema heart in severe hypothyroidism
What happens to the heart in dilated cardiomyopathy?
Decrease in contractility>
global enlargement of the heart
What are signs/sxs of dilated cardiomyopathy?
Biventricular failure
Narrow pulse pressure (d/t decreased SV)
Arrythmias (BBB, Atrial and Ventricular)
How do you diagnose dilated cardiomyopathy?
- Echocardiography shows EF global enlargemnt of the heart
How do you tx dilated cardiomyopathy?
Cardiac transplant
What is the most common cause of sudden death in young athletes?
Hypertrophic cardiomyopathy
What is the genetics behind hypertrophic cardiomyopathy?
Familial form (60-70% of cases)
Autosomal dominant w/ nearly complete penetrance
Young individuals affected
Chromosome 11 and 14 q
What mutation is commonly seen with hypertrophic cardiomyopathy?
Missense mutation in multiple genes>
single aa substitution in contractile protein of cardiac sarcomere
The sporadic type of HCM is associated with what population?
Elderly
How does hypertrophic cardiomyopathy affect the myocardium?
- Greater hypertrophy of the IVS than the free LV wall
- IVS hypertrophy may obstruct blood flow through the LV outflow tract (most pts don’t have severe obstruction of the outflow path)
If there is obstruction to blood flow in hypertrophic cardiomyopathy where is it located?
BELOW the Aortic Valve
What can cause fatal arrythmias and sudden death in hypertrophic cardiomyopathy?
Abberant myofibers in the conducting system
What produces diastolic dysfunction in hypertrophic cardiomyopathy?
LV is non compliant
A pt presents with a harsh systolic ejection murmur (increases with decreased preload), palpable double apical impulse, and angina or syncope with exercise. What do they have?
Hypertrophic cardiomyopathy.
What causes sudden death in hypertrophic cardiomyopathy?
v. tach/fibrillation
How do you diagnose hypertrophic cardiomyopathy?
T-D echocardiograophy
What do you want to avoid when treating hypertrophic cardiomyopathy?
- Avoid strenuous exertion
2. Avoid drugs that decrease preload or increase force of contraction
What is the mainstay of treatment for hypertrophic cardiomyopathy?
Beta blockers
- Decrease HR and Increase diastole (increase preload)
- Decrease myocardial contractility
Implantable cardioconverter defibrillator
Surgery
What causes restrictive cardiomyopathy?
- Amyloidosis ( most common)
- Myocardial fibrosis after open heart surgery
- Radiation
What is hte least common cardiomyopathy?
Restrictive
What happens in restrictive cardiomyopathy?
Decreased ventricular compliance
Diastolic dysfunction type of LHF
What is seen clinically in restrictive cardiomyopathy?
Biventricular heart failure
What is seen on an ECG of someone with restrictive cardiomyopathy?
nonspecific ST-T wave changes
How do you diagnose restrictive cardiomyopathy?
- Echocardiography
2. Cardiac catheterization
How do you treat restrictive cardiomyopathy?
Tx the underlying cuase
