MI Basics

Question 1

What is the most common cause of MI

Answer 1

Rupture of an atherosclerotic plaque, with the development of thrombosis and total occlusion of the artery.

Question 2

Alternative causes of MI (excluding most common)

Answer 2

1. Vasospasm
2. Severe hypotension
3. Excessive metabolic demand
4. Less often embolic event
5. Cocaine use
6. Vasculitis

Question 3

Why does MI occur?

Answer 3

1. Ischemic event affecting cardiac tissue

2. Cardiac muscle is dying due to insufficient oxygen supply

Question 4

Risk factors of MI

Answer 4

Risk factors

1. Male
2. Increasing age
3. Smoking
4. Family Hx
5. HTN
6. DM
7. Dyslipidemia

Question 5

What is the most classic presentation of MI

Answer 5

Crushing chest pain - Increasing in severity lasting longer than 30 min
* 33% pts do not have chest pan esp women and diabetics

Question 6

What are alternative clinical presentations to MI (non-chest pain) symptoms

Answer 6

1. “Indigestion”
2. Often occur early in the morning due to hormone changes
3. Diaphoresis
4. Weakness
5. Anxiety
6. Syncope
7. Restlessness
8. Dyspnea
9. Nausea and Vomiting

Question 7

When does Dressler syndrome occur?

Answer 7

Occurs 1-2 weeks after an MI

Question 8

What are the 5 characterizations of Dressler syndrome?

Answer 8

1. Pericarditis
2. Fever
3. Leukocytosis
4. Pericardial effusion
5. Pleural Effusion

Question 9

What are PE findings of MI

Answer 9

1. Hypertensive OR Hyoptensive
2. Tachycardia OR Bradycardia
3. Lungs may be clear, + rales OR Wheezing
4. JVD
5. Softened Heart Sounds
6. S4 gallop
7. After 12 hours- FEVER may develop
8. *** S4 gallop
9. After 24 hrs Pericardial Friction Rub may develop
10. If 1-2 weeks post myocardial infarction- think Dressler syndrome

Question 10

What serologies would you want to test?

Answer 10

1. Myoglobin,
2. Troponins I and K,
3. CK-MB

Question 11

When cardiac enzyme would be seen in the earlies amount to time?

Answer 11

Myoglobin 1-3 hrs

Question 12

When does myoblobin normalize?

Answer 12

24 hrs

Question 13

When does troponins and CK MB peak?

Answer 13

24 hours

Question 14

Which 2 cardiac enzyme markers rise together?

Answer 14

Troponin and CK-MB

Question 15

What is the troponin cycle?

Answer 15

Elevate 2-12 hours
Peak 24 hours (double elevation time)
Return to normal 2 weeks
(Remember Troponin is on the 2s)

Question 16

What is the CK-MB cycle

Answer 16

Elevated 3-12 hours
Peak 24 hours
Normalizes 72 hours (3 days)

Question 17

Which cardiac enzyme takes the longest to normalize?

Answer 17

Troponin

Question 18

A woman in her 30s went for Mexican food and a movie. She took her jacket off in the movies because she was hot. She felt like she ate too many peppers because of increased indigestion. She was feeling really weak and she left prior to the movie because she felt like she was going to pass out. She was anxious to get home to let the dog out.

Answer 18

Think of MI
1. Diaphoresis
2"Indigestion"
3. Weakness
4. Syncope / Nausea/Vomiting
5. Anxiety/Restless ness