ICL 5.3: Clinical Cardiomyopathies Flashcards
what is a cardiomyopathy?
ventricular muscle disorders resulting in mechanical and/or electrical myocardial dysfunction
what are the main types of cardiomyopathies?
- dilated
- hypertrophic
- restrictive
other = arrhythmogenic right ventricular dysphagia and LV noncompaction
which conditions can progress into dilated cardiomyopathy?
- hypertensive HF
- ischemic HF
- valvular HF
- congenital HF
what are the types of dilated cardiomyopathy?
- idiopathic
- familial = protein mutations
- inflammatory = infectious, noninfectious, peripartum
- toxic = alcohol, chemotherapy, cocaine
- metabolic/nutritional/endocrine = thyroid dysfunction, hypocalcemia
- physiologic = tachycardia, Afib
- neuromuscular
which mutations can lead to dilated cardiomyopathy?
- cytoskeletal proteins
desmin, dystrophin, myosin-binding protein C, titin, sarcoglycans
- myofibrillar proteins
B-myosin heavy chain, troponin, alpha-tropomyosin, actin
- nuclear membrane proteins
lamin A/C
what is the pathophysiology of dilated cardiomyopathy?
myocyte injury —> decreased contractility and SV –> LV dilation and mitral regurgitation because LV starts to dilate and the annulus gets stretched out
then decrease in forward flow leads to fatigue and weakness
increased ventricular filling pressures due to decreased contractility leads to pulmonary congestion (dyspnea, orthopnea, rales) and systemic congestion (JVD hepatomegaly, edema)
what are the signs and symptoms of dilated cardiomyopathy?
- slow progressive onset = weeks to months
- congestion is the main problem = DOE and edema
- lungs = basilar chest dullness due to pleural effusions – cracker
- cardiomegaly
- S3
- mitral regurgitation
what are the venous congestion signs seen in dilated cardiomyopathy?
- JVD
- hepatomegaly
- ascites
- peripheral edema
- RV enlargement due to fluid overload/preload increase
- tricuspid regurgitation due to RV enlargement
what is noninfectious dilated cardiomyopathy?
this is peripartum dilated cardiomyopathy! so it has to present itself in the last month of pregnancy and up to 6 months post-birth
50% recover
what are the risk factors for noninfectious dilated cardiomyopathy?
- older women,
- african american
- multiple pregnancies put you at risk for it
how do you treat noninfectious dilated cardiomyopathy?
if they develop it during pregnancy, avoid nonselective BB like carvedilol; use B1 selective BB – no ACEI because teratogenic –> use hydralazine/nitrate combination to decrease afterload (both are arterial dilators and nitrates also dilate venous)
if the LV EF <25% or if LV dusfunction persists more than 6 months, subsequent pregnancies are not recommended due to SCD
also anticoagulation is recommended because the stasis causes increased risk for thrombus
what is stress cardiomyopathy?
apical ballooning syndrome aka broken heart syndrome
it’s a transient regional systolic dysfunction of LV apex with sparing of the base – the heart looks like a balloon
it present like an acute mI with ST elevation that doesn’t follow a certain coronary artery pattern and therefore the cardiac cath test will show normal coronary arteries
what is the etiology of stress cardiomyopathy?
females > males
postmenopausal women more common
usually you can identify the stress by taking a good history = loss of partners, job, bad news, emotional trigger
what is the pathophysiology of stress cardiomyopathy?
we really don’t now how it happens…
we know there are excess catecholamines and microvascular disease but that’s it (NOT classic epicardial CAD)
what lab results are seen with stress cardiomyopathy? EKG?
EKG abnormal = ST elevation, WT prolongation
troponin (+) and BNP (+)