ICL 5.3: Clinical Cardiomyopathies Flashcards

1
Q

what is a cardiomyopathy?

A

ventricular muscle disorders resulting in mechanical and/or electrical myocardial dysfunction

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2
Q

what are the main types of cardiomyopathies?

A
  1. dilated
  2. hypertrophic
  3. restrictive

other = arrhythmogenic right ventricular dysphagia and LV noncompaction

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3
Q

which conditions can progress into dilated cardiomyopathy?

A
  1. hypertensive HF
  2. ischemic HF
  3. valvular HF
  4. congenital HF
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4
Q

what are the types of dilated cardiomyopathy?

A
  1. idiopathic
  2. familial = protein mutations
  3. inflammatory = infectious, noninfectious, peripartum
  4. toxic = alcohol, chemotherapy, cocaine
  5. metabolic/nutritional/endocrine = thyroid dysfunction, hypocalcemia
  6. physiologic = tachycardia, Afib
  7. neuromuscular
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5
Q

which mutations can lead to dilated cardiomyopathy?

A
  1. cytoskeletal proteins

desmin, dystrophin, myosin-binding protein C, titin, sarcoglycans

  1. myofibrillar proteins

B-myosin heavy chain, troponin, alpha-tropomyosin, actin

  1. nuclear membrane proteins

lamin A/C

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6
Q

what is the pathophysiology of dilated cardiomyopathy?

A

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)

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7
Q

what are the signs and symptoms of dilated cardiomyopathy?

A
  1. slow progressive onset = weeks to months
  2. congestion is the main problem = DOE and edema
  3. lungs = basilar chest dullness due to pleural effusions – cracker
  4. cardiomegaly
  5. S3
  6. mitral regurgitation
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8
Q

what are the venous congestion signs seen in dilated cardiomyopathy?

A
  1. JVD
  2. hepatomegaly
  3. ascites
  4. peripheral edema
  5. RV enlargement due to fluid overload/preload increase
  6. tricuspid regurgitation due to RV enlargement
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9
Q

what is noninfectious dilated cardiomyopathy?

A

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

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10
Q

what are the risk factors for noninfectious dilated cardiomyopathy?

A
  1. older women,
  2. african american
  3. multiple pregnancies put you at risk for it
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11
Q

how do you treat noninfectious dilated cardiomyopathy?

A

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

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12
Q

what is stress cardiomyopathy?

A

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

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13
Q

what is the etiology of stress cardiomyopathy?

A

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

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14
Q

what is the pathophysiology of stress cardiomyopathy?

A

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)

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15
Q

what lab results are seen with stress cardiomyopathy? EKG?

A

EKG abnormal = ST elevation, WT prolongation

troponin (+) and BNP (+)

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16
Q

how do you treat stress cardiomyopathy?

A

treat like HF with B-blockers, ACI, ARBs, diuretics

excellent prognosis; normally recover in months but recurrences are possible

17
Q

what is restrictive cardiomyopathy?

A

RCM has impaired diastole due to loss of compliance from fibrosis of endomyocardial tissue or from infiltration of a noncontractil complex/material into the myocardium

compliance is volume expansion in response to increased pressure and this is lost in RCM

there is a normal EF though until end stage because the cells that can contract will contract till the very end but you just can’t relax as well

18
Q

what are the classes of restrictive cardiomyopathy?

A
  1. noninfiltrative –> idiopathic, scleroderma
  2. infiltrative –> amyloidosis, sarcoidosis
  3. storage diseases –> hemochromatosis, glycogen storage diseases
  4. endomyocardial disease (fibrosis) –> metastatic tumors, radiation therapy, hypereosinophilic syndrome
19
Q

why is there reduced LV filling and CO but the EF is normal?

A

EF = SV/EDV

SV and EDV both decrease

the CO is an absolutely number while the EF is a ratio so that’s why it doesn’t change even though the CO decreases

20
Q

what are symptoms of restrictive cardiomyopathy?

A
  1. fatigue
  2. weakness
  3. DOE
  4. venous congestion
  5. usually HF signs and symptoms
  6. horrible exercise intolerance because they can’t get the volume of filling that they need and it only gets worse with exercise
21
Q

what is the pathophysiology of restrictive cardiomyopathy?

A

rigid myocardium causes increased diastolic pressures which lead to increased systemic and pulmonary venous pressures which can cause R and L HF = JVD, hepatomegaly, ascites, edema

the rigidity means that there’s less ventricular filling and dilation because it can’t expand so you have decreased CO and compensatory increase in HR = fatigue and weakness

22
Q

what are the PE findings seen with restrictive cardiomyopathy?

A
  1. tachycardia
  2. JVD
  3. Kussmaul sign
  4. pulmonary congestion with rales
  5. Afib
  6. tricuspid murmur
  7. ascites
  8. peripheral edema
23
Q

what is Kussmaul sign?

A

an paradoxical increase in jugular venous pressure with inspiration that happens because the RV is also stiff and can’t accommodate higher volumes caused by LV stiffness

seen in restrictive cardiomyopathy

24
Q

what are the diagnostic tests done for restrictive cardiomyopathy?

A
  1. EKG

2. echo

25
Q

what are the EKG findings for restrictive cardiomyopathy?

A
  1. usually nonspecific ST and T wave changes (can be Afib rhythm)
  2. amyloid heart: low voltage and Q waves

3, sarcoid: conduction blocks

26
Q

what are the echo findings for restrictive cardiomyopathy?

A
  1. dilated atria
  2. LV normal/small chamber size from stiffness
  3. LV EF is normal until end stage

you can identify amyloid in the heart by echo based on the strain pattern and it’ll look like LV hypertrophy but NOT based on ECG because amyloid is a noncontractive protein and won’t effect contraction

27
Q

what is constrictive pericarditis?

A

sac around the heart won’t let the heart expand enough

muscle isn’t able to expand so it has really similar presentation to restrictive cardiomyopathy

28
Q

how can you differentiate restrictive cardiomyopathy and constrictive pericarditis?

A
  1. echocardiogram
  2. invasive heart catheterization (hemodynamic study)
  3. CT chest or MRI (thick pericardium in constrictive pericarditis)
  4. EM Biopsy can be helpful too (normal in constrictive pericarditis)
29
Q

how do you treat restrictive cardiomyopathies?

A

we don’t have much to treat this….overlal poor prognosis

symptom relief with medications like diuretics

if it’s caused by hemochromatosis you can do iron chelation

if it’s caused by primary amyloid which means it’s caused by amyloid light chain you can do chemo plus stem cell transplant

if it’s secondary amyloid that means it’s a mutation of the TTR amyloid that can infiltrate the heart and you can treat with new drugs that prevent accumulation of TTR protein

30
Q

what is arrhythmogenic right ventricular dysplasia?

A

the RV gets a fatty infiltration that causes it to dilate so that it’s not able to contract –> replacement of mainly RV free wall by fibrofatty tissues but no idea why

it’s a genetic disorder that’s AD or AR with incomplete penetrance = the presentation is incomplete and not everyone that has AD form will have the phenotype

it’s the gene that codes for desmosomes!!! specifically plakoglobin and demsoplakin that lead to a loss of intercalated discs because the fatty infiltrate gets between the cells and spreads them apart

31
Q

what are the test results that point to arrhythmogenic right ventricular dysplasia?

A
  1. EKG shows an epsilon wave; this is basically pathopneumonic for ARVC!!
  2. dilated RV on echo but MRI is way more useful
  3. cardiac biopsy but not great because lots of false positive
  4. genetic testing when a family member is diagnosed
  5. RV arrhythmias
32
Q

what are the effects of arrhythmogenic right ventricular dysplasia on the heart?

A

the fatty infiltrates mess up the gap junctions which are important for electrical conduction so this lead to palpitations, syncope and SCD!!

the only treatment is an ICD for prevention of SCD

33
Q

what is left ventricular noncompaction?

A

the LV is not compacted; there are trebeculi literally everywhere so you get deep recesses

this is due to a sarcomere mutation!

they cause contraction and relaxation abnormalities which lead to HF and conduction abnormalities that lead to arrhythmias

there’s also a thrombotic risk because of all the stasis happening in all the crevices

34
Q

what is the genetic inheritance of left ventricular noncompaction?

A

AD, AR or x-linked

35
Q

how do you treat left ventricular noncompaction?

A
  1. anticoagulation
  2. ICD
  3. transplant
36
Q

what changes happen to the sarcomere in volume vs. pressure overload?

A

volume overload = sarcomeres added in series = eccentric LV hypertrophy

ex. aortic or mitral regurgitation, ischemic heart disease, dilated cardiomyopathy

pressure overload = sarcomeres added in parallel = concentric LV hypertrophy

ex. chronic hypertension or aortic stenosis