Cardiomyopathies

Question 1

What is dilated cardiomyopathy

Answer 1

most common cardiomyopathy with enlargement and impaired systolic function in one or both ventricles
multiple and varied etiologies (viral, toxic, nutritional)
may also be due to ischemic causes (though post-MI processes are true myopathies)

Question 2

pathology of dilated cardiomyopathy

Answer 2

enlargement and dilation of all 4 chambers
ventricular hypertrophy often seen to decrease wall stress
wall thickness:chamber size is low compared to hypertrophic cardiomyopathy
systolic and diastolic function are both down
histology is variable but may show interstitial fibrosis, necrosis, varied myocytic sizce, and cell infiltrate

Question 3

clinical manifestations of dilated cardiomyopathy

Answer 3

middle age, more men than women if idiopathic
gradual symptoms of fatigue, exertional dyspnea, nocturnal dyspnea, orthopnea, lower extremity edema
prognosis unpredicable, though lower function and greater size are poor prognostic indicators

Question 4

PE of dilated cardiomyopathy

Answer 4

cardiac enlargement, large S4 (diastolic gallop ad blood from systole deccelerates against a stiff, non-compliant ventricle
as disease progresses, you may see rales and S3- the stiff ventricle with elevated diastolic pressures will only fill in early diastole
tricuspid and mitral murmurs
accentuated 2nd heart sound d/t pulm htn
patients have problems with systolic function and exhibit impaired diastolic filling due to ventricular compliance. there is low compliance at high diastolic pressures

Question 5

treatment of dilated cardiomyopathy

Answer 5

remove underlying cause, remove precipitating factors like anemia, infection, meds
alleviate symptoms with O2, rest
give meds like diuretics, digoxin, morphine, vasodilatores (nitrates, hydralazine, ACE-Is).
ACE-Is, and nitrates/hydralzaine have mortality benefit
inotropes are used occasionally in the short term but have a negative impact on mortality in the long-term. BBs may be ok.
consider biventricular pacing to achieve cardiac resynchronization
prophylactic defibrillators

Question 6

What is the cause of hypertrophic cardiomyopathy

Answer 6

genetics- inappropriate cardiac hypertrophy without an altered hemodynamic load like aortic stenosis of HTN
in 1/2 is autosomal dominant; in many others, it is a spontaneous mutation

Question 7

pathology of hypertrophic cardiomyoathy

Answer 7

incr. myocardial mass w/o chamber enlargement
location and extent is variable, though site has an important bearing on the manifestations
hypertrophy is often asymptomatic but commonly involves the interventricular septum

Question 8

asymmetric septal hypertrophy

Answer 8

usually basal and can obstruct LV outflow (LV apex involvement is more common in japan and is more benign).

Question 9

histo of hypertrophic cardiomyopathy

Answer 9

gross disorganization of muscle bundles in both normal and hypertrophic tissue
thickened intramural coronary arterial walls with reduced lumen size

Question 10

Clinical manifestations of hypertrophic cardiomyopathy

Answer 10

with outflow tract obstruction, you must distinguish from aortic stenosis:
valsava: increases thoracic pressure, decreases venous return, and then everything collapses.
variable manifestations that may or may not correlate with severity of hypertrophy. may be asymptomatic, or have dyspnea from impaired ventricular filling.
chest pain and angina common d/t incr. demand, small coronary lumen, low cap density
may have syncope and arrhythmias
may show up as sudden death

Question 11

what is an additional complication/murmur with ASH

Answer 11

left outflow tract obstruction that also destorts the mitral valve apparatus and drwas anterior leaflet of the mitral valve into the left ventricle- mitral regurg

Question 12

Tx of hypertrophic cardiomyopathy

Answer 12

syncope and sudden death associated with strenous exercise- advise against it
scree relatives
antibiotic prophylaxis for endocarditis
improve diastolic filling:
incr. time with BBs or CCBs (CCBs als enhance early relaxation to reduce LV outflow tract)
disopyramide
amiodarone
dual chamber pace-maker
defibrillator, surger, transplant
no diuretics

Question 13

Restrictive cardiomyopathy etiology

Answer 13

least common

may be seen in amyloidosis hemochromatosis, or disease that cause extensive fibrosis

Question 14

pathology of restrictive cardiomyopathy

Answer 14

normal or dilated chambers; firm and thickened chambers, enlarged atria

Question 15

histo of restrictive cardiomyopathy

Answer 15

varied. often has fibrosis and or deposition of iron or amyloid

Question 16

clinical presentation of restrictive cardiomyopathy

Answer 16

variable- often right > left
some arrhythmias, sudden death
orthostatic HTN d/t infiltration of the autonomics
hallmark is impaired diastolic filling. systole also usually affected
prominent y descent