Flashcards in Ischemic Heart Disease & Cardiac Failure Deck (19):
IHD is most commonly due to ___________ of the _______________.
- atherosclerosis of the coronary arteries
What is the normal progression of IHD?
- stable angina --> unstable angina --> MI --> chronic IHD --> sudden cardiac death
T or F: stable angina is associated with reversible injury, while unstable angina and MI are associated with irreversible injury.
- both stable and unstable angina are signs of reversible injury
- MI is irreversible injury
How long can myocardium survive in ischemia before dying?
- 20 minutes
- (this is why angina pain lasts 20 min)
ST depression is the hallmark sign of:
- subendocardial ischemia
- (stable and unstable angina, NSTEMIs)
What is stable angina due to? What about unstable angina? MI?
- stable angina is due to an increased demand of oxygen (ex: during exertion) in the setting of a coronary artery that is at least 70% occluded (from atherosclerosis)
- unstable angina is usually due to the rupture of the atheroma with incomplete occlusion, or when the the artery is 90% occluded from atherosclerosis
- MI: rupture of the atheroma with complete occlusion
Prinzemetal Angina is due to the episodic COMPLETE occlusion of the vessel via vasospasms (the vessel wall clamps down); what type of ischemia will occur? What will we see on ECG?
- complete occlusion will result in transmural ischemia
- as a result, we would expect to see an ST elevation
Subendocardial vs. Transmural ischemia/damage/infarct
- subendocardial results from incomplete occlusion (the ischemia only hits the endocardium because it is the farthest layer); ST depression
- transmural results from complete occlusion (all layers of the heart are deprived of oxygen); ST elevation
Occlusion of the LAD will result in damage to the:
- LV anterior wall and the anterior portion of the interventricular septum
Occlusion of the RCA will result in damage to the:
- LV posterior wall and the posterior portion of the interventricular septum
Why do neutrophils and macrophages enter the ischemic site after an infarction?
- because the infarction leads to necrosis, and acute inflammation (which involves these cell types) always follows necrosis
Pathogenesis of an MI from onset to scarring:
- MI hits: no changes within the first 4 hours -->
- over the course of a day: coagulative necrosis (deep red/dark discoloration of the heart) -->
- over a week: inflammation; first neutrophils (day 1-3) and then macrophages (day 4-7); (yellow pallor from the WBCs in myocardium) -->
- over the first month: granulation tissue (red border around the dead tissue) -->
- 1 month and on: fibrosis (white scar)
IHD is basically synonymous with:
- CAD (coronary artery disease)
Acute Coronary Syndrome
- unstable angina, MI, SCD (sudden cardiac death)
Which coronary artery is most commonly affected in IHD?
- LAD (50% of cases), followed by RCA and then LCX
What will wee see on ECG with a transmural MI?
- ST-segment elevation, pathologic (negative) Q-waves, and decreased R-waves
Acute Heart Failure vs. Chronic Heart Failure
- acute: usually refers to LHF
- chronic: usually refers to L and R HF (AKA congestive heart failure)
Signs and Symptoms of LHF
- *pulmonary congestion/edema* leads to dyspnea, PND, pulmonary crackles