Cardiomyopathies Flashcards Preview

CV Quiz 2 > Cardiomyopathies > Flashcards

Flashcards in Cardiomyopathies Deck (67):
1

What is cardiomyopathy?

heart disease resulting from an abnormality in myocardium

2

What kind of abnormalities occur in cardiomyopathy?

abnormalities in cardiac wall thickness, chamber size, mechanical and/or electrical dysfunction

3

What is primary cardiomyopathy?

confined to heart muscle

4

What is secondary cardiomyopathy?

myocardial involvement as a component of systemic or multiorgan disorder

5

What is dilated cardiomyopathy and what happens?

progressive cardiac dilation: systolic dysfunction, hypertrophy, Enlarged, heavy, flabby, dilated heart, HEART FAILURE, Thrombi may form, Regurgitation- may be due to ventricular dilation (functional regurgitation)

6

x-linked dilated cardiomyopathy is usually caused by mutation in what?

dystrophin gene

7

In 20-50% of dilated cardiomyopathy genetically causes cases what is the mutation?

Predominantly autosomal dominant mutations encoding cytoskeletal proteins like α-cardiac actin, desmin, & nuclear lamins A/C

8

What mutations in the mitochondrial genome cause dilated cardiomyopathy?

Mutations in genes involved in oxidative phosphorylation & fatty acid ß-oxidation

9

What virus usually cause acute viral myocarditis?

Coxasackie B or echovirus usually Self-limited infection in young people

10

How does acute viral myocarditis lead to dilated cardiomyopathy?

Mechanism: unclear– Myocyte cell death and fibrosis– Immune mediated injury– No change with immunosuppressive drugs

11

Two toxins that can cause dilated cardiomyopathy?

Alcohol and doxorubicin

12

What does alcohol do to cause dilated cardiomyopathy?

direct toxic effect myocardium &indirect toxic effect associated with thiamine deficiency lends to beriberi heart disease

13

What does doxorubicin (adriamycin) cause?

Dilated cardiomyopathy and heart failure• Anthracycline toxicity is dose-dependent

14

When does peripartum cardiomyopathy occur?

Late in pregnancy or several weeks to months postpartum

15

Possible causes of peripartum cardiomyopathy?

– Pregnancy-associated hypertension– volume overload– nutritional deficiency– metabolic derangements– immunological reaction– prolactin

16

Dilated cardiomyopathy causes cardiomegaly, what's that?

heart is 2-3 times normal weight & globular appearance

17

Are the valves normal in cardiomyopathy?

Yes, however Mitral or tricuspid regurgitation may be present due to dilation of chamber

18

What are a few other gross morphologies of cardiomyopathy?

• Four chamber dilatation• Variable wall thickness( normal, hypertrophy, flabby)• Mural thrombi

19

What does dilated cardiomyopathy look like on histology?

Histologic changes are not specific for DCM (except for iron overload –stainable) Some fibers may appear stretched or irregular; no necrosisHypertrophy and fibrosis are usual

20

Can iron overload cause dilated cardiomyopathy?

Yes, via Hemochromatosis & Multiple transfusions

21

Increased risk of ldiopathic dilated cardiomyopathy associated with what?

– MALE GENDER– BLACK RACE– HYPERTENSION– CHRONIC BETA-AGONIST USE

22

Clinical presentation of idiopathic dilated cardiomyopathy?

• Heart failure symptoms 75%-85%• Anginal chest pain 8%-20%• Emboli (systemic or pulmonary) 1%-4%• Syncope <1%

23

Prognosis of idiopathic dilated cardiomyopathy?

50% of patients die within 2 years, 25% survive longer than 5 yearsDeath due to cardiac failure, arrhythmia or thromboembolic complications

24

What is Arrhythmogenic Right Ventricular Cardiomyopathy?

Inherited autosomal dominant disease of cardiac muscleright ventricular failure and various rhythem disturbances ventricular tachycardia or fibrillationcan lead to sudden death

25

What is the morphology of Arrhythmogenic Right Ventricular Cardiomyopathy

right ventricular wall is severely thinned because of loss of myocytes, with extensive fatty infiltration and fibrosis

26

• Clinical– Occurs in young adults– Arrhythmias (ventricular tachycardia) – Sudden death – Right ventricular failureWhat is this?

Arrhythmogenic right ventricular cardiomyopathy/dysplasia

27

What is the essential feature of Arrhythmogenic right ventricularcardiomyopathy histology?

fatty infiltration

28

What is Hypertrophic cardiomyopathy (HCM)?

myocardial hypertrophy, poorly compliant left ventricular myocardium leads to abnormal diastolic filling

29

What happens to the heart wall in HCM?

Heart is thick-walled, heavy, and hypercontracting (contrast to flabby heart of DCM)

30

Is diastolic or systolic function affected by HCM?

Primarily diastolic dysfunction; systolic function is usually preserved intermittent left ventricular outflow obstruction

31

Describe ventricular hypertrophy.

– Disproportionate thickening of the septum
– subaortic region (“Banana”shape)
– No ventricular dilatation, ventricle compressed

32

What happens to the atrium in HCM?

Atrium enlarged due to decreased ventricular compliance

33

Describe the histology of HCM.

Marked hypertrophy (>40 µm, normal 15 µm)
Interstitial fibrosis
Myofiber disarray

34

What kinds of genetic components can HCM have?

Missense mutations in genes encoding sarcomeric proteins with Familial, Autosomal dominant, Variable expression

35

Which sarcomeric proteins are usually deffective?

myosin heavy chain β-MHC
myosin binding protein MYBP-C
cardiac TnT

36

How do defects in sarcomeric proteins affect the heart?

Defects in direct sarcomere function and transfer of energy to sarcomere

37

Half of HCM pt have left ventricular outflow tract obstruction what is it?

Caused in two ways:
narrowed left ventricular outflow tract due to hypertrophied interventricular septum or anterior displacement of mitral valve leaflets during systole

38

Mitral valve regurgitation of anterior leaflets & chordae sucked into the outflow tract during mid-late systole causing obstruction secondary to HCM is called what?

Venturi effect

39

Diastolic dysfunction can occur with HCM, how?

the myocardium is stiff, non-compliant
- the left ventricular diastolic pressure is elevated
- the filling of the ventricle in diastole is impaired

40

Due to the hypertrophy of HCM there can be supply/demand mismatch, impaired relaxation during diastole and abnormal intramyocardial arteries which can lead to what?

Myocardial ischemia in the absence significant coronary arteries athersclerosis

41

What arrhythmias can occur as a result of HCM?

1 Paroxysmal supraventricular arrhythmias (Occur in 30-50%)
2 Atrial fibrillation
3 Non-sustained ventricular tachycardia
4 Sustained ventricular tachycardia/ventricular fibrillation (lethal in many pt)

42

Over the course of a lifetime, when does HCM usually present?

Presentation after puberty

43

Signs and symptoms of HCM?

▫ Asymptomatic
▫ Exertional dyspnea due to limitation of cardiac output
▫ Syncope due to left ventricular outflow obstruction
▫ Sudden death in young athletes
▫ Atrial fibrillation with mural thrombus formation

44

Treatment for HCM?

surgical excision & ventricular relaxing drugs

45

Risk factors for cardiac death with HCM:

• Marked ventricular wall hypertrophy (>30mm)
• Young age at presentation (< 40 y)
• History of syncope
• History of aborted cardiac arrest
• Family history of sudden cardiac death
• Certain genetic mutations

46

Pharm treatments of HCM include:

Beta-blockers (first line)
Calcium-channel blockers (in combo or pt who cannot tolerate beta)
Disopyramide

47

Non-pharm therapy includes:

Surgical septal myectomy
Alcohol induced septal ablation (infarction of injected area)
Dual-chamber pacemaker (at RV apex)
Heart transplant

48

Implantable cardioverter-defibrillators can help prevent this serious complication?

Sudden cardiac death

49

What is restrictive cardiomyopathy?

Primary decrease in ventricular compliance,
resulting in impaired ventricular filling during
diastole

50

What are the causes of restrictive cardiomyopathy?

Idiopathic or Secondary to:
– Post-radiation fibrosis
– Amyloidosis
– Sarcoidosis
– Metastases
– Inborn errors of metabolism (Fabry’s disease, Pompe’
s disease)

51

Gross anatomy description is of what disease?
– Normal ventricles (size, wall thickness)
– bi-atrial dilation
– firm myocardium
– interstitial fibrosis

Restrictive cardiomyopathy

52

What is the histology of Restrictive cardiomyopathy?

Patchy or diffuse interstitial fibrosis and disease specific changes

53

Clinical features of restrictive cardiomyopathy?

congestive heart failure with severe pulmonary and hepatic congestion

54

What test would you use to diagnose restrictive cardiomyopathy?

endomyocardial biopsy

55

Types of amyloidosis of the heart?

Senile cardiac amyloidosis: most common
Systemic AA or AL amyloidosis can also involve the heart

56

Causes of senile cardic amyloidosis?

– Transthyretin (prealbumin)– deposits in ventricles and atria
– > 60 yrs age; African-Amer vs. Caucasians = 4:1
– Gene mutation in 4% (isoleucine is substituted for valine), autosomal dominant familial form

57

What does amyloidosis of the heart do to the hemodynamics?

It varies:
– Asymptomatic
– Pressure atrophy of fibers
– Deposition in regions of conduction system leads to arrhythmias

58

Describe the morphology of amyloidosis of the heart.

Heart normal or
firm and rubbery with Eosinophilic
deposits of amyloid

59

Endomyocardial fibrosis, large mural thrombi, peripheral
eosinophilia, eosinophilic infiltrates in organs
Eosinophils release major basic protein which may
cause endomyocardial necrosis and scarring

What cardiomyopathy is this?

Loeffler endomyocarditis

60

Most common in first 2 years of life
Disease of children and young adults in Africafocal or diffuse fibroelastic thickening usually involving mural left ventricular endocardium
What cardiomyopathy is this?

Endocardial fibroelastosis

61

What are the cardiac effects of iron overload?

Heart is usually dilated, rust-brown colored, hemosiderin accumulation, fibrosis may be present

62

Cardiac effects of hyperthyroidism?

tachycardia, palpitations, and cardiomegaly

63

Cardiac effects of hypothyroidism?

CO decreased, fluid accumulation in pericardial sac, flabby enlarged dilated heart

64

Cardiac histological features of hypothyroidism?

myofiber swelling with loss of striations and basophilic degeneration, interstitial mucopolysaccharide-rich edema fluid

65

What is sarcoidosis?

Restriction
Conduction System Disease
Ventricular Arrhythmias
(Sudden Cardiac Death)

66

What are a few cardiotoxic drugs?

Lithium, phenothiazines, chloroquine and cocaine

67

What is Takotsubo cardiomyopathy and what causes it?

Sudden, intense emotional or physical stress leading to acute left ventricular dysfunction which on catecholamines