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Flashcards in MHD: Cardiomyopathy Deck (38):
1

What is a cardiomyopathy?

A primary abnormality of the myocardium not attributable to pressure or volume overload. It involves a progressive impairment of the structure and function of the muscular walls of the heart chambers.

2

What are the 3 main types of cardiomyopathy?

Dilated
Hypertrophic
Restrictive

3

Which type of cardiomyopathy is most common?

Dilated cardiomyopathy

4

Describe the morphological changes seen in dilated cardiomyopathy

Biventricular dilatation causes contractile dysfunction
The myocardium compensates for the dilation with hypertrophy. Interstitial fibrosis can also develop.

5

Proteins of the ________ are involved with genetic forms of dilated cardiomyopathy

Proteins of the CYTOSKELETON are involved with genetic forms of dilated cardiomyopathy

6

What are the non-genetic causes of dilated cardiomyopathy?

Myocarditis
Peripartum (due to elevated PRL)
Toxic
Idiopathic

7

What are the clinical consequences of cardiomyopathy?

Heart failure
Sudden death
Atrial fibrilation
Stroke

8

What is hypertrophic cardiomyopathy?

Marked LV hypertrophy (septum>free wall)
AKA: IHSS, hypertrophic obstructive cardiomyopathy

9

How are diastole and systole affected by dilated cardiomyopathy compared to hypertrophic cardiomyopathy?

Systole is affected by dilated cardiomyopathy
Diastole is affected by hypertrophic cardiomyopathy

10

What is the classical shape of the ventricle in hypertrophic cardiomyopathy?

Banana shaped due to an enlarged intraventricular septum

11

Describe the histology of hypertrophic cardiomyopathy

Myocytes are hypertrophied and appear haphazardly organized. Interstitial fibrosis can also be seen.

12

What is the major cause of hypertrophic cardiomyopathy?

Most cases are familial
Autosomal dominant mutation in gene encoding sarcomeric proteins

13

Mechanically, dilated cardiomyopathy is a defect in ________ whereas hypertrophic cardiomyopathy is a defect in _________

Mechanically, dilated cardiomyopathy is a defect in FORCE GENERATION whereas hypertrophic cardiomyopathy is a defect in ENERGY TRANSFER

14

Clinical outcome of hypertrophic cardiomyopathy

Diastolic heart failure
Exertional dyspnea
Harsh systolic ejection murmur
Anginal pain
Intractable heart failure
Arrhythmias

15

What is the most common cause of sudden death in young athletes?

Hypertrophic cardiomyopathy

16

What is the treatment for hypertrophic cardiomyopathy?

Medications to enhance ventricular contraction (beta blockers, calcium channel blockers)
Surgical excision of muscle

17

What is restrictive cardiomyopathy?

A primary decrease in ventricular compliance prevents ventricular filling (expansion) during diastole (systolic function is preserved)

18

Describe the morphological changes seen in restrictive cardiomyopathy

Enlarged left atrium with are normal LV cavity size, slightly thickened LV wall

19

What are the causes of restrictive cardiomyopathy?

Radiation fibrosis
Amyloidosis
Sarcoidosis
Inborn errors of Metabolism
Endocardial fibroelastosis
Loeffler endomyocarditis

20

What is an amyloid?

A misfolded protein that desposits in the extracellular space causing tissue damage

21

What are the common features of amyloid deposits?

Beta pleated sheet configuration
Stain congo red in tissue that appears apple-green under polarized light

22

What is myocarditis?

Inflammation of the myocardium that causes myocardial injury

23

What are the causes of myocarditis?

Viral (Coxsakie A and B, cytomegalovirus, HIV)
Bacterial (Diptheria, Lyme disease)
Parasitic (Chaga's disease, trichinosis, toxoplasmosis)
Noninfectious (Immune hypersensitivity, rheumatic fever, giant cell myocarditis, sarcoidosis)

24

What is the clinical manifestation of the myocarditis?

Wide spectrum
Can cause acute congestive heart failure, arrhythmias and can progress to dilated cardiomyopathy

25

What liquids can be involved with pericardial effusion?

Serous fluid (clear or yellow)
Blood
Pus

26

How does the timing of pericardial effusion affect the clinical outcome?

Slowly developing may be clinically silent
Rapid or large effusions can compress the atria and vena cava (or ventricles in severe cases), leading to decreased cardiac filling

27

What is pericarditis?

Inflammation of the pericardium usually secondary to cardiac, thoracic or systemic process

28

What are the causes of pericarditis?

Infections (viruses, bacteria, TB, fungi, parasites)
Immune-mediated (rheumatic fever, SLE, post-MI)
Uremia
Neoplasia
Trauma
Radiation

29

What is fibrinous pericarditis?

"Bread and butter" pericarditis
The pericardial surface appears shaggy due to fibrinous exudate
Exam finding: pericardial friction rub

30

What is the cause of suppurative pericarditis?

Acute bacterial infection can lead to purulent surface of the percardium

31

What can cause hemorrhagic pericarditis?

Tuberculosis
Malignancy

32

What can cause caseous pericarditis?

Tuberculosis

33

Describe the presentation of pericarditis

Can be silent, or cause chest pain, systemic complaints
Friction rub is often found on physical exam
EKG changes: diffuse ST elevation

34

Describe the healing process of pericarditis

Focal plaque like thickenings
Mild adhesions
Constrictive pericarditis can cause the heart to be surrounded by a dense scar, which prevents expansion

35

What is the treatment of constrictive pericarditis?

Surgical removal of the scarred, constrictive pericardium

36

What are the complications of cardiac transplantation?

Acute or chronic rejection
Infections
Post tranplant lymphoma
Late progressive diffuse stenosing of coronary arteries

37

What is the success rate of cardiac transplantation?

70-80% 1 year survival
>60% 5 year survival

38

How are heart biopsies obtained?

A bioptome (biopsy tool) is inserted transvenously into the right side of the heart and the biopsy is taken from the septum