Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
56 Cards in this Set
- Front
- Back
|
Can HTN cause cardiomyopathy
|
No. Cardiomyopathies result from a primary myocardial abnormality, excludes HF due to known secondary causes (note:ischemic cardiomyopathy is a misnomer and is caused by CAD)
|
|
|
what is the general cause of cardiomyopathy
|
primary myocardial abnormality
|
|
|
what are the characteristics of dilated cardiomyopathy
|
1. progressive hypertrophy of all 4 chambers
2. dilation of all 4 chambers 3. contraction (systolic) dysfunction 4. progressive CHF |
|
|
what are causes of dilated cardiomyopathy
|
1. idiopathic
2. hereditary (Genetic abnormalities are present in about 20-30% of cases) 3. myocarditis (viral or autoimmune) 4. toxicity: ethanol, cobalt or chemo toxicity (doxorubicin), cocaine 5. peripartum 5. systemic dz (lupus, sarcoidosis, amyloidosis, thyroid dz, hemochromatosis) |
|
|
genetic causes of dilated cardiomyopathy
|
lots of genetic heterogeneity e.g. dystrophin gene or mito enzyme genes
|
|
|
microscopic pathology of dilated cardiomyopathy
|
nonspecific findings: myocyte hypertrophy with boxcar nuclei, interstitial fibrosis, wavy fibers, focal areas of mononuclear inflamm cells
|
|
|
what is the wall thickness like in dilated cardiomyopathy
|
variable- it depends on the degree of dilation (thinner if more dilated). Can be nl, thin, or thick in different regions of the heart
|
|
|
what is the definitive treatment for dilated cardiomyopathy
|
heart transplant (progressive CHF is refractory to txt)
|
|
|
what are common causes of death in dilated cardiomyopathy
|
HF, complications from emboli and ventricular arrhythmias
|
|
|
what are the characteristics of hypertrophic cardiomyopathy
|
1. myocardial hypertrophy
2. abnl diastolic filling (b/c dec CPL) 3. often intermittent ventricular outflow obstruction |
|
|
genetics abnormalities in hypertrophic cardiomyopathy
|
50% of cases inherited as auto dominant inheritance. Defects in genes encoding sarcomeric contractile proteins are critical in development: mutation in beta myosin heavy chain (1/3 cases), tropomyosins, troponins, myosin light chains
|
|
|
what are some gross pathologic features in hypertrophic cardiomyopathy
|
1. severe myocardial hypertrophy
2. marked cardiomegaly 3. IVS often thicker than LV, frequently in subaortic region 4. asymmetric septal hypertrophy (causes outflow obstruction) 5. thickening of mitral leaflet and septal endocardium (due to repeated contact of subaortic septum and anterior mitral valve) 6. LA may be dilated secondary to LV filling dysfunction 7. narrowing of outflow tract (banana shaed) |
|
|
microscopic pathology of hypertrophic cardiomyopathy
|
hypertrophic myofibers with MYOFIBER DISARRAY- haphazard arrangement with ABNL BRANCHING, increased interstitial fibrosis
|
|
|
what kind of cardiomyopathies have ventricular dilation
|
dilated, not hypertrophic
|
|
|
clinical features of hypertrophic cardiomyopathy
|
1. exertional dyspnea
2. harsh systolic ejection murmur 3. myocardial ischemia and angina common 4. high risk of ventricular arrhthymias and sudden death 5. late stage progressive fibrosis can cause CHF |
|
|
characteristics of restrictive cardiomyopathy
|
impaired ventricular filling during diastole (due to decreased V CPL)
|
|
|
etiologies of restrictive cardiomyopathy
|
cardiac amyloidosis is most common, endocardial fibroelastosis, hemachromatosis, sarcoidosis, radiation injury
|
|
|
gross features of cardiac amyloidosis
|
waxy looking infiltrate, varrigation pattern, stiff wall, gray pink subendocardial deposits, mild to moderate cardiomegaly
|
|
|
what are two causes of endocardial fibrosis causing restrictive cardiomyopathy
|
tropical EF and loffler syndrome (LS)
|
|
|
characteristics if Loffler syndrome
|
eosinophilia, dense fibrosis, atrial dilation, thickened endocardium
|
|
|
characteristics of endocardial fibrosis causing restrictive cardiomyopathy
|
dilated atrium, thickend/opaque endocardium, dense fibrosis, ventricular dilation mild or nl
|
|
|
clinical features of restrictive cardiomyopathy
|
1. stiff inelastic ventricle with diastolic dysfunction
2. fatigue, exertional dyspnea, chest pain, arrhthymias 3. CTY decreases with progression leading to CHF |
|
|
what dz do you need to distinguish from restrictive cardiomyopathy
|
constrictive pericarditis- they have similar hemodynamic changes but pericarditic can be treated better surgically
|
|
|
what is the most common familial cardiac disorder
|
hypertrophic cardiomyopathy
|
|
|
what is the prevalence of hypertrophic cardiomyopathy
|
1 in 500
|
|
|
what contributes to obstructive hypertrophic cardiomyopathy
|
hypertrophic IVS, especially in sub aortic region, which causes narrow outflow tract and systolic anterior motion (SAM) of anterior mitral valve leaflet (leaflet gets sucked up by narrowed tract and obstructs outflow)
|
|
|
major sx of hypertrophic cardiomyopathy
|
1. dyspnea
2. angina 3. palpitations 4. sudden cardiac death note: many are asymptomatic |
|
|
what is the pathophysiology of sudden cardiac death in hypertrophic cardiomyopathy
|
myofibril disarray and fibrosis
|
|
|
what increases the risk of developing sudden cardiac death
|
family hx of SCD, hs of syncope, wall thickness >30mm, abnl BP during exercise, non sustained ventricular tachycardia
|
|
|
how do you prevent SCD
|
by implanting a ICD for high risk patients
|
|
|
when does syncope usually occur in hypertrophic cardiomyopathy pts and why
|
during exertion or dehydration from decreased CO or arrhythmias (because decreased ventricular volume causes more mitral valve obstruction to flow)
|
|
|
what is the gold standard imaging technology for diagnosisng HCM
|
echo
|
|
|
PEx findings in HCM
|
S4, harsh crescendo decrescendo systolic outflow murmur, holosystolic murmer (from MR)
|
|
|
how does squatting effect HCM murmur
|
decreases HCM intensity because PL is increased
|
|
|
how does standing effect HCM murmur
|
increases HCM intensity because PL is decreased
|
|
|
how does valsalva effect HCM murmur
|
increases HCM intensity because PL is decreased
|
|
|
how do differentiate an aortic stenosis murmur from an HCM murmur
|
AS murmur increases with increased PL (like with squatting) whereas HCM murmur decreases with increased PL
|
|
|
is HCM a fixed or dynamic obstruction
|
dynamic- decrease in LV size (liek with dehydration) increases the obstuction. Note: AS is a fixed obstruction
|
|
|
what does the EKG look like for HCM
|
meets the criteria for LVH and has diffuse repolarization abnormalities (T wave inversions)
|
|
|
what 3 things must you do to dx HCM
|
EKG, echo, and r/o other causes (note: genetic testing is not required for dx)
|
|
|
what predicts the severity of HCM and the risk of arrhthymia
|
the degree of fibrosis
|
|
|
does the HCM mutation change management of HCM
|
no- genotype and phenotype are not correlated
|
|
|
how do you treat HCM
|
Beta blockers (1st line) and calcium channel blockers for angina sx,
limit exertion, implantable cardioverter defibrillator (ICD) to prevent SCD in pts with >=1 SCD risk factors surgical txt: myectomy or alcohol septal ablation |
|
|
what are the risk factors for prompting ICD implantation with HCM
|
>=1 of the following:
1. family hx of SCD 2. hx of syncope 3. non systematic vent tachy 4. wall thickness>30mm 5. abnl BP with exercise |
|
|
what are the surgical options for HCM
|
myectomy or alcohol septal ablation
|
|
|
what is the gold standard for surgical treatment of HCM
|
myectomy
|
|
|
does myectomy improve sx, mortality of both in HCM pts
|
both
|
|
|
does alcohol septal ablation improve sx, mortality of both in HCM pts
|
sx
|
|
|
what is the pathophysiology of arrhythmogenic right ventricular cardiomyopathy (ARVC)
|
fibrofatty infiltration of RV which frequently results in ventricular arrhythmias
|
|
|
what genetic mutations are found in 50% of ARVC pts
|
desmosomal protein mutations
|
|
|
do dilated cardiomyopathy pts go through a stage of concentric hypertrophy or go straight to eccentric hypertrophy
|
go straight to eccentric hypertrophy
|
|
|
what is eccentric hypertrophy
|
increase in myocyte length, increase in heart mass with an increase in volume of ventricle, myofibrils in series
|
|
|
cardiac features of dilated cardiomyopathy
|
cardiac dilation: increase in myocyte length, fibrosis, myocyte death, cardiac dysfunction, myofibrils in series, eccentric hypertrophy
|
|
|
what is the gold std for dx for dilated cardiomyopathy
|
echo
|
|
|
what criteria has to be met for dx of dilated cardiomyopathy
|
ejection fraction <40% without CAD
|
|
|
how do you txt dilated cardiomyopathy
|
1. if the causes is reversible, treat the underlying dz (e.g. ethanol, thyroid)
2. if HF and remodeling treat with std neurohormonal antagonists (ACE inhibitors, Beta blockers, aldosterone antagonists), resynchronization therapy etc 3. ICD for arrhythmias (if LVEF<35%) 4. don't give prophylaxis for thromboembolitic events because risks>benefits |
