8/12- Pathology of Cardiomyopathies

Question 1

What is another name for hypertrophic cardiomyopathy?

Answer 1

Asymmetric septal cardiomyopathy (?)

Question 2

What is seen in restrictive CM in terms of space between cells (packed or spread)?

Answer 2

Large expansion of interstitial space

Question 3

Causes of DCM?

Answer 3

Mostly idiopathic, and then genetic

• Toxin induced (alcohol, cocaine)
• Infectious
• Autoimmune
• Thyroid disorders

2ndary causes:

• Ischemic (post MI)
• Post inflammatory (after MI)

Question 4

Describe the cardiomyopathies in terms of what you would see on microscopy?

Answer 4

Dilated CM:

• Collagen (interstitial fibrosis) highlighted by Masson’s trichrome stain

Restrictive CM:

• interstitial deposits (e.g. amyloid deposits)

Hypertrophic CM:

• Myocyte disarray, hypertrophy and interstitial fibrosis

Question 5

Case)

• 50 yo male with increasing fatigue, SOB for 6 wks
• Tires, SOB when walking up stairs
• Wakes at night gasping for breath
• Sleeps on 2 extra pillows
• PMH: “cold” that lasted a ong time
• SH: travel to S America for business
• Remote alcohol abuse x 15 yrs

Answer 5

• SOB and extra pillows is indicative of heart failure; can see pulmonary edema

Question 6

What is the most common type of cardiomyopathy?

Answer 6

Dilated CM

Question 7

What is the major dysfunction in DCM?

Answer 7

Systolic dysfunction and congestive heart failure

Question 8

Gross features of DCM?

Answer 8

• 2-3 x heavier
• Large and flabby
• Dilation of all 4 chambers
• Ventricular thickness variable
• Mural thrombi common

Question 9

Microscopic features of DCM?

Answer 9

• Variable myocyte nuclear enlargement and attenuation with irregularity
• Loss of myofibrils in myocytes
• Interstitial and subendothelial fibrosis
• Increased interstitial lymphocytes

Question 10

Case)

• 22 yo basketball player
• Funny feeling in chest for 6 mo, on/off
• PMH
• PE: forceful apical impulse, harsh systolic murmur at L sternal border; LVH on echo

Answer 10

HCM?

Question 11

What demographic does Hypertrophic CM typically affect?

Answer 11

HCM often affects younger age group

Question 12

What are complications/outcomes of HCM?

Answer 12

Commonly causes sudden cardiac death in young asymptomatic person (arrhythmia)

• If symptoms are present, usually have diastolic dysfunction with extertional dypsnea, angina, or non-anginal chest pain, palpitations, syncope
• Harsh systolic ejection murmur

Question 13

Causes of HCM?

Answer 13

• Genetic (involves sarcomere proteins)
• 2ndary: grossly hypertrophic but microscopically minimal change (as in HTN)

Question 14

Gross features of HCM?

Answer 14

• Massive myocardial hypertrophy without ventricular dilation
• On cross-section,

Question 15

Microscopic features of HCM?

Answer 15

• Extensive myocyte hypertrophy
• Haphazard disarry of bundles of myocytes or individual myoctes (myocyt
• Disarray of contractile elements in sarcomeres within cells (myofiber disarray)
• Interstitial fibrosis

Question 16

Case)

• 65 yo female with mild, intermittent chest pain
• SOB, tired no other problems
• PE: pitting edema of legs, hepatomegaly
• ECG: non-specific ST-T changes and low voltage
• Echo: reduced LV function, large atria

Answer 16

RCM

Question 17

Characteristics of Restrictive CM?

Answer 17

• Reduced ventricular compliance an diastolic dysfunction
• Dyspnea, edema, fatigue
• Congestive hepatomegaly, elevated JVP, systolic murmurs from mitral/tricuspid regurgitation

Question 18

What causes RCM?

Answer 18

- Deposition (amyloidosis, hemosiderin in hemochromatosis, etc.)

- Scar formation (radiation, endmyocardial fibrosis)

- Infiltrative (sarcoidosis, hypereosinophilic syndrome)

Question 19

What is seen microscopically in RCM?

Answer 19

• Variable myocardial fibrosis
• Specific findings

Question 20

What are some other cardiomyopathies?

Answer 20

• Arrhythmogenic right ventricular cardiomyopathy
• Noncompaction cardiomyopathy

Question 21

THESE CARDS NEED HELP

Answer 21

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