Myocarditis and other Cardiac Disease

Question 1

What is the most common cause of myocarditis in the US?

Answer 1

Coxsackie virus A and B (more B)

Question 2

What causes myocarditis more in South America?

Answer 2

Chaga’s disease= trypanosoma cruzi

Question 3

What else can cause myocarditis?

Answer 3

• neisseria, borrelia (lyme), or candida albicans

- sarcoidosis, SLE, drugs, radiation

Question 4

What will we see in the heart with myocarditis?

Answer 4

soft focal hemorrhage, mononuclear cell infiltrate (if viral), neutrophil infiltrate (if bacterial), or necrosis.

Question 5

What is giant cell myocarditis?

Answer 5

Has giant cells but also eosinophils, plasma cells, macrophages, and lymphocytes leading to extensive necrosis. Poor prognosis with rapid and lethal clinical course.

Question 6

Does hypersensitivity myocarditis tend to occur in older or younger people?

Answer 6

older, and associated with drug hypersensitivity such as methyldopa. Will see large numbers of eosinophils.

Question 7

What do you see in cardiac sarcoidosis and how do you distinguish it from giant cell myocarditis?

Answer 7

giant cells and noncaseating granulomas, but you won’t see eosinophils or necrosis.

Question 8

What will you see in lymphocytic myocarditis?

Answer 8

lots of lymphoctyes

Question 9

How do pts present with myocarditis?

Answer 9

most are asymptomatic and will be self limiting. Others however may have lethal arrhythmias or develop into dilated cardiomyopathy.

Question 10

What is arrhythmogenic right ventricular dysplasia?

Answer 10

inherited disease causing right ventricular failure and rhythm disturbances (ventricular tachycardia or fibrillation) and can lead to sudden death (especially in young people).
It is related to defective cell adhesion proteins in the desmosomes that link adjacent cardiac myocytes causing thin right ventricle.

Question 11

What drugs have been linked to myocardial injury?

Answer 11

cocaine, lithium, phenothiazides, and chloroquine. Also chemo and immunotherapy drugs.

Question 12

Can intense catecholamine (vasopressor) stimulation cause myocardial damage?

Answer 12

YES. Also pheochromocytoma can cause this.

Question 13

What does amyloidosis do to the myocardium?

Answer 13

deposition of insoluble extracellular fibrillar material forming beta-pleated sheets. Senile (deposition of transthyretin) has better prognosis than systemic amyloidosis.
Looks like amorphous pink material around the myocytes.

Question 14

**How do we stain for amyloidosis?

board question

Answer 14

congo red, which produces an apple green birefringence.

Question 15

What causes iron overload?

Answer 15

hemochromotosis or multiple blood transfusions.

Question 16

What will iron overload cause?

Answer 16

deposits in the ventricles and myocardium and may produce systolic dysfunction by acting on the metal dependent enzyme systems, or by inducing oxygen free radical injury.
It will give the heart a rusty-brown color and myocytes may accumulate hemosiderin.