Card - Path (Part 3: Ischemic Heart Disease & MI) Flashcards
Pg. 287-289 in First Aid 2014 Sections include: -Ischemic heart disease manifestations -Evolution of MI -Diagnosis of MI -Types of infarcts -ECG diagnosis of MI -MI complications
What defines angina? Include what causes it and whether angina causes myocyte necrosis.
Chest pain due to ischemic myocardium secondary to coronary artery narrowing or spasm; no myocyte necrosis
What are 3 types of angina?
(1) Stable (2) Variant angina (Prinzmetal) (3) Unstable/Crescendo
To what is stable angina usually secondary?
Usually secondary to atherosclerosis
Characterize the pain and ECG findings of stable angina.
Exertional chest pain in classic distribution (usually with ST depression on ECG), resolving with rest
What is another name for Variant angina? When does it occur, and to what is it secondary?
Occurs at rest secondary to coronary artery spasm
What ECG finding characterizes Variant angina (Prinzmetal)?
Transient ST elevation on ECG
What are 3 known triggers of Variant angina (Prinzmetal)? What is often the case in terms of the trigger?
Known triggers include tobacco, cocaine, and triptans, but trigger is often often
How can Variant angina (Prinzmetal) be treated?
Treat with calcium channel blockers, nitrates, and smoking cessation (if applicable).
What defines Unstable/Crescendo angina?
Thrombosis with incomplete coronary artery occlusion
Describe the chest pain and ECG finding of Unstable/Crescendo angina.
ST depression on ECG (increase in frequency or intensity of chest pain; any chest pain at rest).
What are 5 types of ischemic heart disease manifestations?
(1) Angina (2) Coronary steal syndrome (3) Myocardial infarction (4) Sudden cardiac death (5) Chronic ischemic heart disease
What defines Coronary steal syndrome? Give 2 examples of the type of substance involved. What is an important clinical correlation for this?
Distal to coronary stenosis, vessels are maximally dilated at baseline. Administration of vasodilators (e.g., dipyridamole, regadenoson) dilates normal vessels and shunts blood toward well-perfused areas => decreased flow and ischemia in the poststenotic region; Principle behind pharmacologic stress
What most often defines and causes myocardial infarction?
Most often acute thrombosis due to coronary artery atherosclerosis with complete occlusion of coronary artery and myocyte necrosis
What will the ECG show in transmural versus subendocardial myocardial infarction?
If transmural, ECG will show ST elevation; if subendocardial, ECG may show ST depressions.
What is used to diagnose myocardial infarction?
Cardiac biomarkers are diagnostic
What defines sudden cardiac death, and what most commonly causes it?
Death from cardiac causes within 1 hour of onset of symptoms, most commonly due to a lethal arrhythmia (e.g., ventricular fibrillation).
What are 3 conditions associated with sudden cardiac death, and what is important to relate to each?
Associated with CAD (up to 70% of cases), cardiomyopathy (hypertrophic, dilated), and hereditary ion channelopathies (e.g., long QT syndrome).
What defines chronic ischemic heart disease?
Progressive onset of CHF over many years due to chronic ischemic myocardial damage.
What are the 3 most commonly occluded arteries leading to MI? List them in order of most to least common.
LAD > RCA > Circumflex
What 7 symptoms characterize MI?
Symptoms: (1) diaphoresis (2) nausea (3) vomiting (4) severe retrosternal pain (5) pain in left arm and/or jaw (6) shortness of breath (7) fatigue
What gross myocardial changes occur at the following time periods after an MI: (1) 0-4 hr (2) 4-12 hr (3) 12-24 hr (4) 1-3 days (5) 3-14 days (6) 2 weeks to several months?
(1) None (2) & (3) [Occluded artery]; Infarct, Dark mottling; Pale with tetrazolium stain (4) Hyperemia (5) Hyperemic border; central yellow-brown softening - maximally yellow and soft by 10 days (6) [Recanalized artery], Gray-white (scar)
What changes can be seen under light microscope at the following time periods after an MI: (1) 0-4 hr (2) 4-12 hr (3) 12-24 hr (4) 1-3 days (5) 3-14 days (6) 2 weeks to several months?
(1) None (2) Early coagulative necrosis, release of necrotic cell contents into blood; edema, hemorrhage, wavy fibers (3) Neutrophil migration starts. Reperfusion injury may cause contraction bands (due to free radical damage) (4) Extensive coagulative necrosis. Tissue surrounding infarct shows acute inflammation with neutrophils. (5) Macrophages, then granulation tissue at margins (6) Contracted scar complete
Again, what microscopic change(s) occur(s) 0-4 hr after onset of an MI? What are 4 complications that may occur in this time frame? What is important to know about these complications?
None; (1) Arrhythmia (2) HF (3) Cardiogenic shock (4) Death; These are the 4 complications that can occur within the first 24 hours after onset of an MI
Again, what microscopic change(s) occur(s) 4-12 hr after onset of an MI? What are 4 complications that may occur in this time frame? What is important to know about these complications?
Early coagulative necrosis, release of necrotic cell contents into blood; edema, hemorrhage, wavy fibers; (1) Arrhythmia (2) HF (3) Cardiogenic shock (4) Death; These are the 4 complications that can occur within the first 24 hours after onset of an MI