Hypertrophic Cardiomyopathy Flashcards
What is it?
genetic diseases
hypertrophy as compensatory mechanism for mutations in contractile proteins of sarcomere
If asymmetric septal hypertrophy AND subaortic stenosis are featured…
hypertrophic obstructive cardiomyopathy
Most common cause of…
sudden death in young athletes under the age of 35
atherosclerotic disease is most common cause of sudden death in athletes over age 35
epidemiology
young adults
males
clinical presentation
asymptomatic until mid-20s
pathogenesis
decreased compliance –> increased LV, LA, and pulmonary pressures
In 30% of cases, there is also outflow obstruction due to rapid flow, with Venturi forces…
…drawing the anterior leaflet of the mitral valve toward a bulging upper septum, sometimes with mitral regurgitation and atrial fibrillation
Gross pathology
wall thickening (up to 5 x normal thickness; average of 2 cm though)
asymmetric hypertrophy of basal (upper) septum
thickened anterior leaflet of mitral valve and mirror-image patch of fibrosis on the bulging septum
Microscopic pathology
myocyte disarray
myocyte hypertrophy
interstitial and replacement fibrosis
–in haphazard plexiform pattern
Complications
HF IE atrial fibrillation LA mural thrombus formation syncope sudden death
Symptoms
dyspnea angina syncope lightheadedness on standing sudden death
Signs
S4
rough crescendo-decrescendo systolic murmur at left sternal border
(**increased w/ standing or Valsalva maneuver…OPPOSITE of aortic stenosis)
double apical impulse
diagnosis
Sometimes genetic testing
echo
treatment
preclusion from sports
preclusion from drugs (BBs, CCBs, antiarrhythmics)
implanted defibrillator if necessary
If severe subaortic obstruction…
a wedge of hypertrophied septum can be surgically excised or ablated by:
–injection of poison (specifically, alcohol) into the first septal perforator coronary artery to infarct part of the hypertrophied septum.
