Cardio15 Flashcards
Evolution of MI
What are the most common coronary artery occlusion sites?
Left Anterior Descending - 1st
Right Coronary Artery - 2nd
Circumflex Artery - 3rd
What are the symptoms of MI?
Diaphoresis Nausea/Vomiting Retrosternal Pain Pain in left arm and/or Jaw SOB Fatigue
Evolution of MI: 0-4 hours
- Light Microscopy:
- Risk:
Evolution of MI: 0-4 hours
- Light Microscopy:
- NONE
- Risk:
- Arrythmia
- CHF exacerbation
- Cardiogenic shock
Evolution of MI: 4-12 hours
- Light Microscopy:
- Risk:
Evolution of MI: 4-12 hours
- Light Microscopy:
- Early Coagulative Necrosis
- Edema
- Hemorrhage
- Wavy fibers
- Risk:
- Arrhythmia
Evolution of MI: 12-24 hours
- Light Microscopy:
- Risk:
Evolution of MI: 12-24 hours
- Light Microscopy:
- Contraction bands (d/t reperfusion injury)
- Release of Necrotic cell content into Blood
- NEUTROPHIL infiltration (begins)
- Risk:
- Arrythmia
Evolution of MI: 1-3 days
- Light Microscopy:
- Risk:
Evolution of MI: 1-3 days
- Light Microscopy:
- Extensive COAGULATION NECROSIS
- Acute inflammation (tissue surrounding infarct)
- NEUTROPHIL migration
- Risk:
- Fibrinous pericarditis
Evolution of MI: 3-14 days
- Light Microscopy:
- Risk:
Evolution of MI: 3-14 days
- Light Microscopy:
- MACROPHAGE infiltration
- GRANULATION tissue at margins
- Risk:
- Free wall rupture leading to TAMPONADE
- Papillary muscle rupture
- Ventricular aneurysm
- Interventricular septal rupture (d/t Macrophages degradation of structural components)
Evolution of MI: 2 weeks-months
- Light Microscopy:
- Risk:
Evolution of MI: 2 weeks-months
- Light Microscopy:
- Contracted scar complete
- Risk:
- Dressler’s syndrome
When do you see wavy fibers?
4-12 hours post-MI
When do you see Contraction bands?
12-24 hours post-MI
When do you see Coagulation necrosis?
1-3 days post-MI
When do you see neutrophil migration?
1-3 days post-MI (begins 12-24 hours post)
When do you see macrophage infiltration?
3-14 days post-MI
Why is there referred pain to neck and shoulder region during an MI?
Afferent pain fibers of Heart enter the Posterior Horn of spinal cord @ same level as brachial plexus
What is the gold standard for diagnosing an MI?
ECG - within first 6 hours
hat is the most specific protein marker found in blood following an MI?
Cardiac troponin I
When do you see a rise in Cardiac troponin I?
4 hours post-MI
Remains elevated for 7-10 days
What protein marker is useful in diagnosing reinfarction following acute MI?
CK-MB
-Levels return to normal after 48 hours
*predominantly found in myocardium but can also be released from skeletal muslce
What are types of infarct?
Transmural & Subendocardial
What are the ECG changes in a Transmural infarct?
ST Elevation
Q waves
What are the ECG changes in Subendocardial infarcts?
ST Depression
Describe Transmural infarct.
INcreased necrosis
Affects entire wall
ST Elevation & Q waves on ECG
Describe Subendocardial infarcts.
d/t Ischemic Necrosis of <50% of ventricle wall
*Subendocardium especially vulnerable to ischemia
ST Depression on ECG
ECG diagnosis of MI: Anterior Wall
- Artery:
- Leads w/Q waves:
ECG diagnosis of MI: Anterior Wall
- Artery: LAD
- Leads w/Q waves: V1-V4
