L4 - MI

Question 1

STEMI is caused by what?

Answer 1

Occlusion

Question 2

Somebody with STEMI needs what most?

Answer 2

Surgery to open occlusion

Question 3

What does STEMI look like on ECG?

Answer 3

Low R wave
High ST
Inverted T wave

Question 4

What is the diagnosis if see ST elevation?

Answer 4

If in anterior leads = anterior infarction

If in inferior leads = inferior infarction

Question 5

What are the anterior leads?

Answer 5

1
AVL
V1-V6

(AVR not in either classification cuz right on the border)

Question 6

What artery supplies the areas of the anterior leads?

Answer 6

LAD

Question 7

What are the inferior leads?

Answer 7

2
3
AVF

(AVR not in either classification cuz right on the border)

Question 8

What artery supplies the areas of the inferior leads?

Answer 8

Supplied by right coronary artery

Question 9

Is inferior or anterior infarction worse?

Answer 9

Anterior/LAD is worse

Question 10

Describe the evolution of the coronary thrombi?

Answer 10

Thin cap over lipid core only occludes vessel about 40%. No problem

Something causes corner of cap to rupture & spill lipid –> platelets aggreagate to prevent spillage of lipid = Mural thrombosis with some stenosis

RBCs aggregate with platelets to form thrombis –> occlusion –> 0 or near 0 flow

Question 11

What layers of muscle are effected first during infarction & why?

Answer 11

Subendocardial

farthest from blood supply

Question 12

How do the different layers of muscle get injured vs. time?

Answer 12

@ 30 min = subendocardial necrosis

4 hours = subepicardium necrosis

6-12 hours = entire wall

Question 13

What is the catch phrase which stresses quick action for MI?

Answer 13

Time is muscle

Question 14

What is the term for time from patient arrival to start of catheterization? Target?

Answer 14

Door to balloon time

2 hours

Question 15

What is it called when the cath lab, the cath technicians and cardiologists are all told of MI patients arrival & need for surgery?

Answer 15

STEMI alert

Question 16

What cardiac markers are currently used for MIs? When do they first raise above normal?

Answer 16

Troponin & CK-MB

4 hour after injury

Question 17

What is the most sensitive cardiac marker?

Answer 17

Troponin

Question 18

Patient has had chest pain for 3 hours but normal troponin. Diagnosis?

Answer 18

Still could be MI, too early for troponin to be raised

Question 19

With relation to MI, crackles in the lungs is a sign of what?

Answer 19

Pulmonary edema

Question 20

How is ejection fraction measured?

Answer 20

Echo

Question 21

Chronic MI treatment/prevention?

Answer 21

Control risk factors

Lowering lipids…

Question 22

Acute MI management?

Answer 22

Nitrates

Beta blocker

ACEI for LV dysfunction

Aspirin or Clopidigrel/Plavix (anti-platelet aggregation)

Heparin (anti-coagulant)

Question 23

If not near a hospital & angiography is not available, how do you open an occlusion?

Answer 23

Thrombolytic agents

Question 24

Who should not receive nitrates during acute Mi management?

Answer 24

Somebody with a BP that is already low

Question 25

What is the best way to administer nitrates? Why?

Answer 25

IV

Can shut it off if BP gets too low. Transdermal & sublingual stay in system for hours

Question 26

Who should not receive beta blockers during the management of acute MI?

Answer 26

Low BP or HR

Question 27

Who should receive beta blockers during the management of acute MI?

Answer 27

Atrial fib with high HR

Question 28

What is the relationship of death & echo ejection fraction? “Tipping point”?

Answer 28

As ejection fraction increases, deaths decrease

If have 40% ejection fraction, have a decent shot at being ok

Question 29

What is normally occurring during ST segment? Why is ST segment elevated in MI?

Answer 29

Ventricle should already be depolarized & atria have already returned to normal = flat line

During injury of the heart, some cells are depolarizing or repolarizing when they shouldn’t be