(ACS) Acute Coronary Syndrome

Question 1

Acute Coronary Syndrome

Answer 1

Umbrella term for conditions where: Blood flow to the heart is suddenly blocked

Question 2

ACS

Answer 2

1. STEMI
2. NSTEMI
3. Unstable Angina

• all three involve plaque + platelet aggregation
• Only STEMI + NSTEMI include a thrombus

Question 3

Angina types

Answer 3

1. Printzmetal’s Variant Angina
   (vasospasm)
   -SUPPLY ISCHEMIA
   -Not from atherosclerosis
2. Chronic Stable Angina
   (fixed stenosis)
   -DEMAND ISCHEMIA
3. Unstable Angina
   (thrombus)
   -SUPPLY ISCHEMIA

Question 4

Prinzmetal Angina: Cause

Answer 4

Coronary artery spasm

-From endothelial dysfunction (damage)

Question 5

Prinzmetal Angina: Characteristics

Answer 5

Unique Features

• CAD (Atherosclerosis) may or may not be present
• Onset timing: Rest, minimal exertion, night
• Elevated ST SEGMENT

Question 6

ACS: Unstable Plaque

Answer 6

1. Size of Lipid core?
   - Large
2. Inflammation?
   - Active
3. Smooth muscle cells?
   - Proliferation into intima

Question 7

Unstable Angina

Answer 7

Chest pain occurring for the first time
-Myocardial Ischemia

Chest pain more severe than usual with chronic angina

• New regions of the heart are undergoing myocardial ischemia
• First nitro doesn’t stop pain

EMERGENCY situation

Question 8

Unstable Angina Characteristics

Answer 8

Ruptured plaque + thrombus formation

Why is there no infarction?
-Occlusion is PARTIAL OR thrombus DISSOLVES

ECG Changes:
-Might see ischemic changes, typically transient

Cardiac enzymes elevated?
-NO

Question 9

Key characteristics of Plaque rupture

Answer 9

Large lipid core

Thin cap

Question 10

Theory of plaque Rupture

Answer 10

INCREASED SNS ACTIVITY
(exercise, stress, circadian rhythm)
-Inc BP, HR, Force of contraction
-Inc force of coronary artery blood flow
-Inc force exerted against injured epithelium

PLAQUE RUPTURE

• platelets adhere to ruptured plaque
• release of substances
  1. attract more platelets
  2. contribute to vasospasm

THROMBUS FORMATION

Question 11

ACS vs Stable Angina

Answer 11

Stable Angina: <15 mins
-treated w/rest

ACS: >20 mins

• more pain
• n/v, diaphoresis…

Question 12

Signs of ACS: MEN

Answer 12

MEN:

• Discomfort or tingling in arms, back, neck, shoulder, or jaw
• Chest pain
• SOA

Question 13

Signs of ACS: WOMEN

Answer 13

WOMEN:

• Fatigue
• Sudden dizziness
• Heartburn-like feeling
• Cold sweat
• N/V

Question 14

Signs of MI

Answer 14

• Diaphoresis
• Dyspnea
• Extreme anxiety
• Levine’s sign (Fist to chest)
• Pallor
• Retrosternal crushing chest pain that radiates to shoulder, arm, jaw, or back.
• Weak pulses

Question 15

What is an ACUTE MI?

Answer 15

Rupture of plaque and then thrombus formation
-Blood flow disruption is prolonged or totally stopped

ST-Elevation or not
Inc Troponin

Question 16

ACUTE MI Definition

Answer 16

Acute coronary syndrome (ACS) with prolonged ischemia without recovery

Myocardial cells suffer irreversible ISCHEMIC NECROSIS

Either STEMI or NSTEMI

Question 17

From Ischemia to Infarction

Answer 17

Ischemia causes lack of blood flow»> less O2»» less ATP production»> cells can’t work

Irreversible injury occurs in: 30min to 4hrs
(why REPERFSION should be done within 4hrs)

Tissue necrosis: by 4hrs

Necrotic tissue is cleared away by: 1-2 weeks

Tough fibrous scar tissue replaces necrotic tissue by:
6 Weeks

Question 18

Ischemia, Injury, and Infarction: 3 zones of tissue damage

Answer 18

1. Infarction (Necrosis)
   - MI, dead cells
   - No recovery for this tissue
2. Injury
   - Some recovery possible
   - can be reperfused
   - Not dead yet…
3. Ischemic
   - Full recovery possible

Do not want the patient to make it worse and extend the size of infarction
GOAL: Inc O2, Decrease heart’s demand

Question 19

Acute MI: Extent of damage depends on 3 factors….

Answer 19

1. LOCATION OR LEVEL of occlusion in the coronary artery
2. LENGTH OF TIME that the coronary artery has been occluded
3. Heart’s availability of COLLATERAL CIRCULTION

Question 20

STEMI

Answer 20

ST-segment: Elevated
QRS: Wide
T wave: Peaked, then invert
Troponin: Elevated
Size of infarct: large
Outcomes: Poor

Question 21

NON-STEMI

Answer 21

ST-segment: Depressed or normal
QRS: normal
T wave: Inverted
Troponin: Elevated
Size of infarct: Smaller
Outcomes: Better

Question 22

LAD

Answer 22

Left Anterior Descending

• Supplies Left Ventricle
• Most common place for MI

WIDOW MAKER

Question 23

ECG Tombstoning

Answer 23

Elevated ST segment With PEAKED Rounded T-wave (tombstone shaped)
-Indicates a large myocardial area is experiencing ischemia (POOR OUTCOME)