Flashcards in Quiz 2 Deck (20)
Myocardial dysfunction commonly occurs due to
different conditions such as ischemic heart disease, hypertension and valvular heart disease.
Less frequently observed is cardiac disease
whose cause is intrinsic to the myocardium itself, such as inflammatory disorders of the heart, immunologic diseases, systemic metabolic disorders, muscular dystrophies, genetic abnormalities of cardiac muscle cells and diseases of unknown etiology.
Cardiomyopathy describes what?
The term cardiomyopathy (literally, heart muscle disease) is used to describe heart disease resulting from a primary abnormality in the myocardium.
The 3 major categories of cardiomyopathy are:
- Dilated (90% of all cases of non-ischemic cardiomyopathy); most common form of non-ischemic cardiomyopathy
Characterized by enlargement and dilatation of all four chambers of the heart
Many of these cases have no known etiology and are referred to as idiopathic dilated cardiomyopathy.
What are the 1st and 2nd most common causes in the US for dilated cardiomyopathy?
The most common cause of non-ischemic dilated cardiomyopathy in the U.S. is chronic alcoholism.
Viral myocarditis may also result in dilated cardiomyopathy.
Shape of a very large heart in dilated cardiomyopathy
globoid shape because all of the chambers are dilated.
HCM is characterized by myocardial hypertrophy, abnormal diastolic filling and in about one third of cases, intermittent ventricular outflow obstruction.
Other names from Hypertrophic Cardiomyopathy
Hypertrophic cardiomyopathy (HCM) is also known by such terms as idiopathic hypertrophic sub-aortic stenosis and hypertrophic obstructive cardiomyopathy.
HCM is characterized by myocardial hypertrophy,
abnormal diastolic filling and in about one third of cases, intermittent ventricular outflow obstruction.
Microscopically, the heart demonstrates what with myocardial hypertrophy?
of myocardial fibers (which
also have prominent dark
nuclei) along with interstitial
is a genetic disease, caused by a mutation in any one of several genes that encode proteins that within the sarcomere, the contractile unit of cardiac muscle.
How does the structure of the heart change with hypertrophic cardiomyopathy
The heart becomes thick-walled, heavy, and hyper-contracting, in contrast to the flabby, hypo-contracting heart of DCM
Often only one ventricle is hypertrophic.
The essential feature of HCM
massive myocardial hypertrophy without ventricular chamber dilation
A classic appearance of HCM is the disproportionate thickening of the ventricular septum as compared with the free wall of the ventricle.
In restrictive cardiomyopathy
the myocardium is usually infiltrated with abnormal tissue that results in impaired ventricular wall motion with abnormal ventricular wall contraction and relaxation.
The most common causes of restrictive cardiomyopathy
are amyloidosis and hemochromatosis.
How does Hemochromatosis occur in the heart ?
of iron can lead to heart
enlargement and heart
failure. Cardiomyopathy due
to hemochromatosis is a form
of restrictive cardiomyopathy
What does amyloid deposition look like microscopically?
deposits of pale pink material
between myocardial fibers.
This is characteristic for amyloid.
What does Endocarditis generally refer to?
to inflammation on the valve leaflets, although the endocardial lining of the atrium and ventricles may also be involved, especially after surgery.