Cardiomyopathies 2 Flashcards
sarcoidosis restrictive cardiomyopathy (cardiac sarcoid) - overview
*noncaseating sarcoid granulomas can deposit in the heart, causing whitish tissues (sarcoid) and an associated scar
*characterized by the presence of non-caseating granulomas on histology
prevalence of cardiac sarcoidosis
*only 5% of people with sarcoidosis have CLINICAL evidence of cardiac involvement, but on autopsy 70% have cardiac involvement
*most likely symptom/clinical manifestation of cardiac sarcoidosis = VENTRICULAR TACHYCARDIA
echo findings of clinical sarcoidosis
*thin LV septum
*thin LV wall
*ventricular aneurysms, particularly in the inferolateral wall
*systolic dysfunction with LV dilation
Loeffler’s Endocarditis / Endomyocardial Fibrosis - causes
*eosinophilic states that may result in Loeffler’s endocarditis include:
-hypereosinophilic syndrome
-eosinophilic leukemia
-carcinoma
-lymphoma
-drug reactions
-parasites
Loeffler’s Endocarditis / Endomyocardial Fibrosis - pathogenesis
*eosinophilia & eosinophilic penetration of the cardiac myocytes leads to a fibrotic thickening of the endocardium
*commonly, the heart will develop large mural thrombi (thrombi which lay against the ventricle walls) due to deterioration of LV wall muscle contractility
Loeffler’s Endocarditis / Endomyocardial Fibrosis - symptoms
*edema
*breathlessness
*the disease is commonly contracted in temperate climates (due to favorable conditions for parasites)
*rapidly fatal
Fabry’s Disease - overview
*an X-linked disease of lysosomal metabolism, resulting in attenuated activity or, in most males, absence of the enzyme alpha-galactosidase A (alpha-Gal A)
*as a result, the breakdown of glycosphingolipids is impaired, leading to systemic lysosomal accumulation of Gb3
Fabry’s Disease - diagnosis
*enzyme assay (usually done on leukocytes) to measure the level of alpha-galactosidase activity
Fabry’s Disease - symptoms
*cardiac complications
*peripheral neuropathy
*renal complications
*GI motility
Fabry’s Disease - imaging/EKG
*EKG findings: symmetrical T-wave inversion across the prochordium
*echo: muscle function normal but thickened wall
*coronary angiography shows that the coronaries are wide open
*cardiac MRI: thickened muscle; deposition of Gb3
hemochromatosis - overview
*characterized by an accelerated rate of intestinal iron absorption and progressive iron deposition in various tissues
*most common presentation is hepatic cirrhosis, in combination with: hypopituitarism, cardiomyopathy, diabetes, arthritis, hyperpigmentation
*autosomal RECESSIVE trait
iron deposition cardiomyopathy (due to hemochromatosis)
*deposition of iron in the cardiac muscle, leading to a restrictive cardiomyopathy
*heart is dilated due to iron deposition
*treatment with phlebotomy allows the heart to remodel back to normal shape
hypertrophic cardiomyopathy (HCM) - overview
*abnormal muscle thickness without increased afterload (i.e. hypertension or aortic stenosis) due to a GENETIC ABNORMALITY, most likely with the SARCOMERE
*characterized by myocyte disarray
*affects 1 in 500 people
hypertrophic cardiomyopathy vs. concentric left ventricular hypertrophy
*hypertrophic cardiomyopathy: genetic; REGIONAL LV wall thickening
*concentric LVH: due to pressure overload (aortic stenosis, HTN); GLOBAL LV wall thickening
hypertrophic cardiomyopathy - histology
*disarray in the arrangement of the myocytes relative to normal myocytes
genetics of hypertrophic cardiomyopathy
*genetic mutations associated with the SARCOMERE, such as: myosin binding protein C and beta-myosin heavy chain
hypertrophic cardiomyopathy - types
- asymmetric septal hypertrophy without resting murmur
- obstructive hypertrophic cardiomyopathy, associated with the classic murmur (this is the type we are usually referring to)
- mid-ventricular HCM with associated apical aneurysm
- apical HCM
obstructive hypertrophic cardiomyopathy & Venturi Effect
*very thick septum can lead to abnormal motion of mitral valve during systole
*mitral valve gets sucked toward the septum, obstructs flow into the aorta
hypertrophic cardiomyopathy - symptoms
*dyspnea
*angina (chest pain)
*syncope
*sudden death
*S4 SYSTOLIC MURMUR
therapy for LVOT obstruction in hypertrophic cardiomyopathy
*medical therapies:
-disopyramide (Na+ blocker)
-beta-blockers
-verapamil (Ca blocker)
-mavacamten
*if not relieved by medical therapy, options:
1. alcohol septal ablation (once balloon inflated, infuse alcohol, which causes infarction of the thickened portion of the septum)
2. surgical myectomy (removal of excess myocardial tissue)
hypertrophic cardiomyopathy - clinical manifestations
*myofibrillar disarray → increased risk of ventricular arrhythmias (es. ventricular tachycardia) → sudden cardiac death
hypertrophic cardiomyopathy & sudden cardiac death risk factors
*prior cardiac arrest
*family members with sudden death caused by HCM
*unexplained syncope
*non-sustained ventricular tachycardia
*patients whose blood pressure falls during exercise
*extreme thickness of left ventricular wall (33 mm or more)
arrhythmogenic right ventricular cardiomyopathy (ARVC) - overview
*inherited disease involving FIBROFATTY REPLACEMENT of the right ventricle myocardium leading to conduction abnormalities and arrhythmias
*primary risk is that it can induce malignant ventricular arrhythmias → sudden cardiac death
*if certain criteria met, need ICD
*no cure
*epsilon wave on EKG
“unclassifiable” cardiomyopathies
- Takotsubo cardiomyopathy (stress-induced cardiomyopathy)
- left ventricular noncompaction cardiomyopathy
Takotsubo cardiomyopathy (stress-induced cardiomyopathy) - typical presentation
*emotional malady/intense feelings can cause the HEART TO CHANGE SHAPE
*ventricular apical ballooning likely due to INCREASED SYMPATHETIC STIMULATION (i.e increased release of catecholamines)
*often precipitated by emotional stress, but can be instigated by physiologic stress as well (surgery, trauma, illness)
*with the apical involvement, you worry about the left anterior descending artery, but it’s completely open
Takotsubo cardiomyopathy (stress-induced cardiomyopathy) - treatment
*supportive care
*perhaps tx with beat blocker to protect from over-stimulation by epinephrine or norepinephrine
*expect 100% recovery
left ventricular noncompaction cardiomyopathy
*noncompacted layer of cardiac tissue; significant trabeculations; muscle function is poor
*REFRACTORY CHF, VENTRICULAR TACHYCARDIA, and STROKES occurring in young individuals were the 3 things that demarcated this condition
*ventricular tachycardia because some of these tissues conduct electricity
*typically seen in younger individuals
*complications include cardiac shock, pulmonary edema, stroke
