Car 19 - Myocardial Infarction Part 1 Flashcards
Which artery is most likely be occluded by atherosclerosis?
Left anterior descending artery. Therefore anterior wall MI most common.
What gross and microscopic features do we see 4-12 hours in the evolution of an MI?
Gross: Dark mottling. Micro: Necrosis and hemorrhage.
What gross and microscopic features do we see 12-24 hours in the evolution of an MI?
Gross: Dark Mottling. Microscopic: Contraction bands, coagulative necrosis, neutrophil immigration.
How do we lower the risk of arrhythmias in patients w/ MI?
Keep K+ above 4. Keep Mg above 2.
What gross and microscopic features do we see 1 to 3 days in the evolution of an MI?
Gross: Dark mottling, Hyperemia. Microscopic: Coagulative necrosis, extensive inflammation, neutrophil infiltration.
What gross and microscopic features do we see 3 to 14 days in the evolution of an MI? What are risks and other findings associated with this time?
Gross: Yellow-tan softening. Micro: Macrophage infiltration. Risks: Ventricular aneurysm, Wall rupture, Papillary muscle rupture.
What gross and microscopic features do we see more than two weeks after in the evolution of an MI? What are risks and other findings associated with this time?
Gross: Gray-white scar. Micro: ^ collagen deposition, decreased cellularity. Risk: Dressler syndrome (Post-MI pericarditis), Ventricular aneurysm.
What are the three types of Acute coronary syndrome (ACS)?
ST segment elevation (STEMI). Non-ST segment elevation (NSTEMI). Unstable angina.
How do we diagnose ST segment elevation (STEMI)?
We see elevation of ST segments. AND if we have a patient with chest pain + new left bundle branch block.
What are some EKG changes w/ MI (always obtain a previous EKG for comparison!).
ST segment elevation of at least 1 mm in 2 contiguous leads. T-wave inversion. New LBBB. New Q waves (at least 1 block wide or 1/3 height of the total QRS complex).
Which enzyme is the most specific for cardiac muscle damage and why?
Troponin I. B/c it pops up in 4 hours and lasts for 2 weeks.
What 3 serum lab do we look for in MI?
Troponin I. CK-MB. CPK.
What is the most common lethal complication after a myocardial infarction?
Arrhythmia.
RFF: Chest pain, pericardial friction rub, and persistent fever occurring several weeks after an MI.
Dressler syndrome.
What is the treatment for Dressler syndrome?
An autoimmune pericarditis, treated with NSAIDs like aspirin.
