Diseases of the myocardium Flashcards
A group of diseases of the myocardium associated with mechanical or electrical dysfunction that usually show dilation or hypertrophy are are due to many things
Cardiomyopathy
Cardiomyopathy is traditionally classified into
3 morphological patterns
What are the 3 morphological patterns of cardiomyopathy
dilated (congestive) (most common)
Hypertrophic
Restrictive (obliterative or infiltrative)
Characterized by dilation and impaired ineffective contraction of one or both ventricles (usually left)
Dilated cardiomyopathy
In dilated cardiomyopathy, the __ of the heart is impaired and patients may develop overt heart failure, atrial and or ventricular arrhythmias, or sudden cardiac death
systolic function
Most common of the 3 patterns of cardiomyopathy (60% of cases)
Dilated cardiomyopathy
Causes of dilated cardiomyopathy
Genetic (20-50%)
Chronic alcoholism (15-40%)
sleep apnea
(LOTS others)
In most patients with dilated cardiomyopathy symptoms of __ develop
congestive heart failure
Mitral regurgitation may be present with
Dilated cardiomyopathy
In dilated cardiomyopathy the hear is usually __ due to __
enlarged and heavy
dilation of all four chambers (histologically insignificant)
Marked thickening of the left ventricular wall of 15 mm or more without dilation
Hypertrophic cardiomyopathy
Not explained by another cardiac or systemic disorder
Hypertrophic cardiomyopathy
What is also profoundly enlarged and hypertrophied in hypertrophic cardiomyopathy
interventricular septum
Hypertrophic cardiomyopathy may result in hemodynamically significant obstruction with in the __
left ventricular outflow tract
HCM associated with LVOT obstruction is called
idiopathic hypertrophic subaortic stenosis (IHSS)
There is usually reduced __ in HCM
stroke volume
Most cases of HCM are __ in multiple genes encoding proteins of the __
genetic
cardiac sarcomere and calcium regulation
Characterized by massive left ventricular hypertrophy without ventricular dilation. Disproportionate thickening of the ventricular septum relative to the left ventricular free wall
HCM
What shape does the left ventricle take in HCM
banana-shaped
about 1/3 of patients with HCM have a function obstruction of the __
left ventricular outflow tract
3 main microscopic abnormalities in HCM
Massive myocyte
Disorganized myocyte architecture
interstitial and replacement fibrosis
restrictive ventricular filling
Restrictive cardiomyopathy
A decrease in ventricular compliance and distensibility (Stiff) resulting in impaired ventricular filling during diastole
Restrictive cardiomyopathy
The atria frequently become enlarged (ventricles = normal)
Restrictive cardiomyopathy
Least common of the 3 patterns of cardiomyopathy
Restrictive cardiomyopathy
2 Common causes of Restrictive CM
amyloidosis
Progressive systemic sclerosis
Biventricular congestive heart failure is common
Restrictive CM
Are one or both atria typically dilated in restrictive CM
Both
Microscopically this is found with restrictive CM
interstitial fibrosis
