L22

Question 1

Define myocardial ischemia

Answer 1

O2 demand > O2 supply to heart muscle

Question 2

Define myocardial infarction

Answer 2

Thrombosis due to rupture of atherosclerotic plaque

Question 3

3 factors that determine heart O2 demand

Answer 3

1. HR
2. Contractility
3. Wall tension - P and volume

Question 4

Name the 6 steps of the ischemic cascade

Answer 4

1. ↓O2 to heart muscle
2. Switch to anaerobic metabolism
3. Relaxation abnormalities - diastole
4. Contraction abnormalities - systole
5. ST changes to EKG
6. Angina

Question 5

Myocardial ischemia might present as angina. What are the 3 types of angina?

Answer 5

1. Chronic, stable = angina pectoris
2. Variant = prinzmetal’s
3. Unstable (this is also under the umbrella of acute coronary syndrome)

Question 6

Symptoms of stable angina

Answer 6

Visceral, deep pain
Self described around the sternum
“Elephant on my chest”

Question 7

Provocation & palliation of stable angina

Answer 7

Onset: stress - physical or emotional

Relieved by stopping stress

Question 8

Stable angina is usually due to…

Answer 8

Atherosclerosis

Existing block leads to less BF during activity –> stress induced pain

Question 9

Remember the 6 risk factors for atherosclerosis

Answer 9

1. High cholesterol
2. HTN
3. Smoking
4. Diabetes
5. Age
6. Family history CHD

Question 10

EKG for stable angina

Answer 10

ST depression when episodic

Question 11

Describe variant angina

• Presentation
• EKG changes

Answer 11

Spontaneous chest pain - at rest

EKG = transient ST elevation

Question 12

Cause variant angina + treat

Answer 12

Coronary artery spasm

Treat w/ nitrates or CaCBs

Question 13

What are the 3 conditions under the umbrella term “acute coronary syndrome”?

Answer 13

= conditions that result of plaque rupture and some de
1. NSTEMI
2. STEMI
NSTEMI and STEMI are both types of MI
3. Unstable angina

Question 14

What is STEMI

Answer 14

MI w/ ST elevation
Transmural infarct = through entire myocardial thickness
Usually result of complete occlusion of that area’s blood supply

Question 15

What is NSTEMI

Answer 15

Non-ST elevated MI
May see ST depression
Subendocardial infarction = less invasive

Question 16

Presentation of acute coronary syndromes

Answer 16

1. Crushing chest pain at rest
2. Gripping chest = Levine sign
3. Sweating

Question 17

What is a white thrombus? What kind of occlusion does it cause?

Answer 17

Platelet clot
Partially occlusive - b/c platelets, think soft!
Causes unstable angina or NSTEMI

Question 18

What is a red thrombus? What kind of occlusion does it cause?

Answer 18

Fibrin clot
Complete occlusion - big hard clot
Causes STEMI

Question 19

How do women present with MI?

Answer 19

Atypically:
Shoulder/neck pain
Dyspnea
Fatigue

Question 20

Tests to diagnose MI for pt presenting with chest pain

Answer 20

1. Resting EKG - if clean get exercise EKG to bring out perfusion issues
2. Troponin levels
   +/- Coronary arteriogram

Question 21

What EKG finding indicates prior MI?

Answer 21

Q wave
Dip before the QRS
= No electrical activity somewhere = dead tissue

Question 22

If you see a Q wave in leads 2, 3, avF - which coronary artery is affected?

Answer 22

RCA

Question 23

What are concerning findings for exercise test:

• HR onset
• Recovery: late vs early
• ST changes?
• Hypo or hypertension?

Answer 23

HIGH RISK RESULTS:
- Early onset bradycardia
- Late recovery - over 7 mins 
- ST depression
- Hypotension
Findings for AGGRESSIVE APPROACH

Question 24

What is a cold spot on myocardial perfusion tests? Findings for ischemic vs infarcted tissue?

Answer 24

Cold spot = not taking up radioisotope b/c no BF = ischemic area
Ischemic = transient cold spot
Infarcted tissue = fixed cold spot

Question 25

2 drugs for pharm stress test

Answer 25

Dobutamine - B1 agonist - increases contractility | Regadenoson = adenosine receptor agonist (duh!) = arteriolar dilation

Question 26

What are findings on echo for ischemia vs infarction?

Answer 26

Ischemia = transient abnormality Infarction = fixed Same as perfusion, different test

Question 27

Treat CAD

Answer 27

1. Revascularize - PCI = angioplasty +/- stent - CABG 2. Meds - Nitrates = vasodilators - BBs - Ca CBs GOALS reduce O2 consumption of myocardium

Question 28

Vessels that can be used for CABG

Answer 28

Saphenous vein graft | Internal mammary artery

Question 29

Describe nitrate mechanism

Answer 29

Dilation veins >> arteries Pool blood in circulation Decrease preload

Question 30

Describe nitrate effects on heart

Answer 30

Vasodilate coronary arteries to increase subendocardial flow (to possibly ischemic areas) Less wall tension/pressure because decrease preload Net: increased HR and contractility

Question 31

SE nitrates

Answer 31

Headache - drop BF to brain as blood pools peripherally | Hypotension - SO much venous pooling

Question 32

Why do we give BB for MI?

Answer 32

Decreases mortaility

Question 33

Why do we give BB for angina pectoris?

Answer 33

↓HR and contractility | Net ↓O2 consumption

Question 34

Which BBs are cardio specific?

Answer 34

``` B1s A-M blockers aka B1s are the 1st 1/2 alphabet Acebutolol Atenolol Betaxolol Carvedilol Esmolol Lavetalol Metroprolol ```

Question 35

SEs BBs

Answer 35

``` Fatigue HF Excessive bradycardia Worsen diabetic control Bronchoconstriction ```

Question 36

Which type of angina are Ca CBs helpful with?

Answer 36

Variable

Question 37

Mechanism of CaCBs for ACS therapy

Answer 37

Both vasodilators Non-DHPs - ↓HR DHPs - ↓BP

Question 38

Most important CAD med

Answer 38

Aspirin

Question 39

Is immediate opening of the occlusion more significant for MIs w/ elevated or depressed ST segments?

Answer 39

STEMI | Indicates complete occlusion - get back profusion ASAP

Question 40

Should you give fibrinolytics or go to the cath lab?

Answer 40

Under 90 mins - cath lab | Otherwise fibrinolytics