Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
8 Cards in this Set
- Front
- Back
|
two main types of infarctions
|
- subendocardial infarcts affect inner 1/3 to 1/2 of LV
- transmural infarcts affect full LV wall thickness |
|
|
transmural infarcts
- left anterior descending artery region |
- ANTERIOR, apical, anteroseptal walls
- most common type |
|
|
transmural infarcts
- right coronary artery region |
- INFERIOR infarct (posterior 1/3 to 1/2 or interventricular septum)
|
|
|
transmural infarcts
- left circumflex coronary artery region |
- LATERAL wall of LV
- least common type |
|
|
gross appearance
- acute MI - healed MI |
- acute - pallor with a central pale yellow region bordered by a red hyperemic zone
- healed - scarring, firm pale gray |
|
|
histologic progression of MI
- first 24 hrs - 2-3 days - 5-7 days |
- first 24 hrs - intracellular edema, nuclear chromatin clumping and migration, release of intracellular proteins (myoglobin, troponins, etc)
- 2-3 days - necrotic myocytes attract NEUTROPHILS - 5-7 days - neutrophils replaced by macrophages, collagen deposition |
|
|
reperfusion of ischemic myocardium
- good? - bad? |
- good - neutrophils have better access and repairs more rapidly
- bad - hemorrhagic due to blood flow through damaged microvasculature, cell damage mediated by reactive oxygen species (ROS) >>> ^Ca2+ >> hypercontraction |
|
|
complications of MI
|
- arrhythmias - account for half of all deaths by ischemic heart >> premature ventricular beats, sinus bradycardia, tachycardia, complete heart block
- LV failure and cardiogenic shock - extension of infarct - rupture of the free wall of the myocardium >> pericardial tamponade!! - LV aneurysms - mural thrombosis and embolism - pericarditis |
