Cardiomyopathy

Question 1

What is cardiomyopathy?

Answer 1

Group of myocardial diseases that result in cardiac dysfunction.

Question 2

What are the three types of Cardiomyopathy?

Answer 2

1. Dilated Cardiomyopathy
2. Hypertrophic Cardiomyopathy
3. Restrictive Cardiomyopathy

Question 3

What is Dilated Cardiomyopathy?

Answer 3

Dilation of all four chambers of the heart

Question 4

What is the most common form of cardiomyopathy?

Answer 4

Dilated Cardiomyopathy

Question 5

What does dilated cardiomyopathy result in?

Answer 5

Systolic dysfunction (ventricles can’t pump), leading to biventricular CHF

Question 6

What complications are associated with dilated cardiomyopathy?

Answer 6

Mitral and tricuspid valve regurgitation and arrhythmia!

Question 7

What is the most common cause of dilated cardiomyopathy?

Answer 7

Idiopathic

Question 8

What are other causes of dilated cardiomyopathy?

Answer 8

1. Genetic mutation (usually autosomal dominant)
2. Myocarditis
3. Alcohol abuse
4. Drugs (e.g. Doxorubicin & cocaine)
5. Pregnancy –> seen during late pregnancy or soon (weeks to months) after childbirth
6. Hemochromatosis

Question 9

What is the pathogenesis of Myocarditis that leads to dilated cardiomyopathy?

Answer 9

Usually due to Coxsackie A or B

• Characterized by lymphocytic infiltrate to the myocardium
• Results in chest pain, arrhythmia with sudden death or heart failure
• Dilated cardiomyopathy is a late complication

Question 10

Side note: What is Hemochromatosis?

Answer 10

Excess body iron leading to deposition in tissues (hemosiderosis) and organ damage (hemochromatosis)
–> tissue damage is mediated by generation of free radicals

Question 11

Side note: What causes Hemochromatosis?

Answer 11

Due to autosomal defect in iron absorption (primary) or chronic transfusions (secondary)
–> Primary hemochromatosis is due to mutations in the HFE gene, usually C282Y

Question 12

Side note: What does Hemochromatosis present with?

Answer 12

Late adulthood

• Classic triad = cirrhosis, secondary diabetes mellitus, and bronze skin
• Other findings: dilated cardiomyopathy, cardiac arrhythmias, gonadal dysfunction (due to testicular atrophy)

Question 13

Side note: What do labs show in Hemochromatosis?

Answer 13

Inc. ferritin, Dec. TIBC, Inc. serum iron, Inc. percent saturation

Question 14

Side note: What does liver biopsy show in Hemochromatosis?

Answer 14

Accumulation of brown pigment in hepatocytes

-Prussian blue stain distinguishes iron (blue) from lipofusion

Question 15

Side note: What cancer is associated with hemochromatosis? How do you treat hemochromatosis?

Answer 15

• Increased risk of hepatocellular carcinoma

- Treatment is phlebotomy

Question 16

What is Hypertrophic Cardiomyopathy?

Answer 16

Massive hypertrophy of left ventricle

Question 17

Who usually has hypertrophic cardiomyopathy?

Answer 17

Young athletes

Question 18

What causes Hypertrophic Cardiomyopathy?

Answer 18

• Usually due to genetic mutations in sarcomere proteins

- Most common form is autosomal dominant

Question 19

What are the clinical features of Hypertrophic Cardiomyopathy?

Answer 19

1. Decreased cardiac output - Left ventricular hypertrophy leads to diastolic dysfunction (ventricle cannot fill)
2. Sudden death due to ventricular arrhythmias - hypertrophic cardiomyopathy is a common cause of sudden death in young athletes
3. Syncope with exercise - Subaortic hypertrophy of the ventricular septum results in functional aortic stenosis

Question 20

What does biopsy show in Hypertrophic Cardiomyopathy?

Answer 20

Myofiber hypertrophy and disarray

Question 21

What is restrictive cardiomyopathy?

Answer 21

Decreased compliance of the ventricular endomyocardium that restricts filling during diastole

Question 22

What are causes of restrictive cardiomyopathy?

Answer 22

-Amyloidosis, Sarcoidosis (hemochromatosis), fibroelastosis (children), and Loeffler syndrome (endocardial fibrosis with an eosinophilic infiltrate and eosinophilia)

Question 23

How does restrictive cardiomyopathy present?

Answer 23

Presents as CHF

Question 24

What do you see on EKG with classic restrictive cardiomyopathy?

Answer 24

Low voltage EKG with diminished QRS amplitude