Cardiomyopathies

Question 1

Dilated Cardiomyopathy

Answer 1

Mostly familial (autosomal dominant) with globoid shape
All chambers are dilated with impairment of contractility
Hypertrophy of myocytes and fibrosis
EF is lower than 40%

Key words: dilated chambers, massive hypertrophy, and interstitial fibrosis

Question 2

Causes of Dilated Cardiomyopathy

Answer 2

Toxicity: thiamine deficiency, cobalt cardiotoxicity, chemo drugs

Post myocarditis

Peripartum: occurs in the last month before delivery and post 5 months delivery

Iron overload aka iron heart that doesn’t pump very well from hemochromatosis and transfusions

Supraphysiologic stress: catecholamine induced, pheochromocytoma, cocaine, and takotsubo cardiomyopathy

Question 3

Clinical Feature of Dilated Cardiomyopathy

Answer 3

20-50 years old
CHF, tricuspid/mitral valve regurgitation
Sudden cardiac death

Question 4

Hypertrophic Cardiomyopathy

Answer 4

Asymmetric septal hypertrophy
Cardiomegaly
Thick septum LV outflow tract obstruction
Diastolic dysfunction

Myofiber disarray is the buzzword – “bananas are going crazy”

Autosomal dominant mutations in sarcomeric protein genes

Question 5

Clinical Features of Hypertrophic Cardiomyopathy

Answer 5

Can cause sudden cardiac death = need to detect this
Impaired L ventricular diastolic filling*
Harsh systolic ejection murmur

Question 6

Arrthymogenic Right Ventricular Cardiomyopathy (ARVC)

Answer 6

Yellow of R ventricle = all fat; not just replaced by fat, but thinned and dilated so not functioning well at all

Systolic disorder of RV with recurrent VT and RV origin with focal RV adiposity

Desmosome protein deficiency in myocytes

Question 7

Clinical Features of ARVC

Answer 7

More common in Italy mostly in males 15-50 years old
Naxos Syndrome: palmar and plantar keratosis with wooly hair

Clinical Presentation: syncope or sudden cardiac death from heart failure arrhythmia

Question 8

Restrictive Cardiomyopathy

Answer 8

Diastolic disorder
Decrease in ventricular compliance, but normal LV size
Biatrial dilation with mural thrombi
Systolic function is often normal

Question 9

Restrictive Cardiomyopathy Causes

Answer 9

Infiltrative Diseases:
Radiation fibrosis
Amyloidosis*** 
Sarcoidosis
Metastatic tumor

Loeffler endomyocarditis: associated with eosinophils and myeloproliferative disorders

Question 10

Amyloid Restrictive Cardiomyopathy

Answer 10

Amyloid are proteins that are floating around in blood and deposit wherever
Firm, waxy texture with thick ventricles, and endocardial deposits

Buzz word: Apple green birefringence

Question 11

Sarcoidosis Restrictive Cardiomyopathy

Answer 11

Big nodules

Microscopically is non-caseating granulomas within the myocardium and epicardial fat

Question 12

Restrictive Cardiomyopathy: Endomyocardial Fibrosis and Fibroelastosis

Answer 12

Endomyocardial fibrosis in Africa and tropical regions – unknown causes of fibrosis (idiopathic)

Endocardial fibroelastosis: babies under 2 months of age; blue glistening color of the heart because cartilaginous material is present

Question 13

Myocarditis

Answer 13

Weeks to years after infective myocarditis
Pathogens: enterovirus, T. cruzi (Chaga’s disease = kissing bug with protozoan parasites), T. gondii (cat litter and pregnant women), and HIV

Lymphocytic= viral infections; show lymphocytic infiltrates