Pathology of Cardiomyopathies

Question 1

What is cardiomyopathy?

Answer 1

a group of myocardial diseases that result in cardiac dysfunction.

Question 2

What is dilated cardiomyopathy?

Answer 2

dilation of all 4 chambers of the heart.

Question 3

What is the most common form of cardiomyopathy?

Answer 3

DILATED cardiomyopathy

Question 4

In what does dilated cardiomyopathy result?

Answer 4

systolic dysfunction (ventricles cannot pump), leading to biventricular CHF, with complications of mitral and tricuspid regurgitation and arrhythmia (because you are stretching the conduction systems).

Question 5

What is the most common cause of dilated cardiomyopathy?

Answer 5

idiopathic (we don’t know).

Question 6

What are other causes of dilated cardiomyopathy?

Answer 6

• genetic mutations (autosomal dominant mostly, but if x-linked then dystrophin problem).
• myocarditis (coxsackie A or B)= lymphocytic infiltrate
• alcohol (leading to thiamine deficiency= beriberi disease).
• drugs (doxorubicin and cocaine)
• pregnancy
• hemochromatosis
• viral myocarditis is the most common cause in young.

Question 7

What is the treatment for dilated cardiomyopathy?

Answer 7

heart transplant

Question 8

What is hypertrophic cardiomyopathy?

Answer 8

massive hypertrophy of the left ventricle and septum.

Question 9

**What causes hypertrophic cardiomyopathy?

Answer 9

genetic mutations in sarcomere proteins of beta myosin heave chain (autosomal dominant).

Question 10

**What occurs with hypertrophic cardiomyopathy?

Answer 10

1. decreased CO (LVH leads to diastolic dysfunction= ventricle cannot fill due to lost compliance).
2. most common GENETIC cause of SUDDEN DEATH due to ventricular arrhythmias (especially in young athletes).
3. syncope with exercise (from functional aortic stenosis).

Question 11

**What is the classic finding in a biopsy of hypertrophic cardiomyopathy?

Answer 11

myofiber hypertrophy with disarray.

Question 12

What is restrictive cardiomyopathy?

Answer 12

decreased compliance of the ventricular endomyocardium that restricts filling during diastole.

Question 13

What are the causes of restrictive cardiomyopathy?

Answer 13

• amyloidosis
• sarcoidosis (non-caseating granulomas)
• endocardial fibroelastosis (children).
• Loeffler syndrome= endomyocardial fibrosis with an EOSINOPHILIC infiltrate.

Question 14

How do patients with restrictive cardiomyopathy present?

Answer 14

as CHF with low-voltage EKG and diminished QRS amplitude.

Question 15

What is the normal weight of the heart?

Answer 15

take a person’s weight in lbs, double it, and that should be the weight of their heart in grams.
ex. 150 lbs x 2= 300 (thus 300 grams).