deck_5046985 Flashcards
What is a primary cardiomyopathy?
diseases of the heart muscle typically confined to myocardium
What is a secondary cardiomyopathy?
systemic cause of the cardiomyopathy (e.g. hemochromatosis)
What are the three types of cardiomyopathy?
-dilated (congestive)-hypertrophic (most common form)-restrictive (some kind of infiltrate in the myocardial muscle or pericardium prevents normal beating of the heart)
Which chambers are dilated in dilated cardiomyopathy?
all of them
What is the most common cause for dilated cardiomyopathy?
chronic alcoholism
Other causes of dilated cardiomyopathy?
-some may be the end-stage of remote viral myocarditis caused by coxsackievirus V and other enteroviruses)-dystrophin gene mutations
What meds could cause dilated cardiomyopathy?
doxorubicin
Describe the gross appearance of a heart with dilated cardiomyopathy?
flabby, all chambers dilated, wall thinning accompanies the dilationventricular thickness varies
What are some potential consequences of dilated cardiomyopathy?
-mural thrombi due to stasis near the margins of the dilated chambers, leading to emboli-valvular regurgitation
What is Beriberi heart disease?
chronic alcoholism is associated with thiamine deficiency (vitamin B1) historically present in places where polished rice were a large part of the diet
What are the two major types of beriberi?
-Wet beriberi-Dry beriberi and Wenicke-Korsakoff syndrome
What does wet beriberi affect?
CV system causing congestive heart failure
What does dry beriberi affect?
nervous system causing neurologic and/or psychiatric symptoms
What does hypertrophic cardiomyopathy cause?
-diastolic dysfunction (impaired contractility) -can result in idiopathic hypertrophic sub aortic stenosis (IHSS)
What causes idiopathic hypertrophic sub aortic stenosis (IHSS)?
asymmetric interventricular septal hypertrophy that pushes into the left ventricle and can close off the aortic valve
How does hypertrophic cardiomyopathy look grossly?
interventicular septum comrpesses ascending aorta and the left atrium is usually enlarged
How does hypertrophic cardiomyopathy look microscopically?
cardiac fibers are in disarray and run in many directions and become surrounded by collagen
So what do you see in hypertrophic cardiomyopathy?
- marked left ventricular hypertrophy- asymmetric bulging of a very large inter ventricular septum into the left ventricular chamber- reduced SV and impaired diastolic filling and overall smaller chamber size-deceased left ventricular compliance
The abnormal areas caused by hypertrophic cardiomyopathy can lead to what?
arrhythmias
Many (most) cases of hypertrophic cardiomyopathy are caused by what?
mutations in genes encoding for sarcomeric proteins (B-myosin heavy chain)
What do defects in B-myosin heavy chains cause?
defects in energy transfer from mitochondria to sarcomeres and/or direct sarcomere dysfunction
What are some causes of restrictive cardiomyopathy?
anything that infiltrates the pericardium and impairs ventricular filling (diastolic) such as amyloidosis, hemochromatosis, or radiation-induced fibrosis
How does restrictive cardiomyopathy present?
-ventricles are normal size-cavities are not dilated-myocardium is firm -bi-atrial dilation is common due to decreased ability of ventricles to fill