Ischemic Heart Disease & Cardiac Failure

Question 1

IHD is most commonly due to ___________ of the _______________.

Answer 1

• atherosclerosis of the coronary arteries

Question 2

What is the normal progression of IHD?

Answer 2

• stable angina –> unstable angina –> MI –> chronic IHD –> sudden cardiac death

Question 3

T or F: stable angina is associated with reversible injury, while unstable angina and MI are associated with irreversible injury.

Answer 3

• false!
• both stable and unstable angina are signs of reversible injury
• MI is irreversible injury

Question 4

How long can myocardium survive in ischemia before dying?

Answer 4

• 20 minutes

- (this is why angina pain lasts 20 min)

Question 5

ST depression is the hallmark sign of:

Answer 5

• subendocardial ischemia

- (stable and unstable angina, NSTEMIs)

Question 6

What is stable angina due to? What about unstable angina? MI?

Answer 6

• 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

Question 7

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?

Answer 7

• complete occlusion will result in transmural ischemia

- as a result, we would expect to see an ST elevation

Question 8

Subendocardial vs. Transmural ischemia/damage/infarct

Answer 8

• 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

Question 9

Occlusion of the LAD will result in damage to the:

Answer 9

• LV anterior wall and the anterior portion of the interventricular septum

Question 10

Occlusion of the RCA will result in damage to the:

Answer 10

• LV posterior wall and the posterior portion of the interventricular septum

Question 11

Why do neutrophils and macrophages enter the ischemic site after an infarction?

Answer 11

• because the infarction leads to necrosis, and acute inflammation (which involves these cell types) always follows necrosis

Question 12

Pathogenesis of an MI from onset to scarring:

Answer 12

• 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)

Question 13

IHD is basically synonymous with:

Answer 13

• CAD (coronary artery disease)

Question 14

Acute Coronary Syndrome

Answer 14

• unstable angina, MI, SCD (sudden cardiac death)

Question 15

Which coronary artery is most commonly affected in IHD?

Answer 15

• LAD (50% of cases), followed by RCA and then LCX

Question 16

What will wee see on ECG with a transmural MI?

Answer 16

• STEMI

- ST-segment elevation, pathologic (negative) Q-waves, and decreased R-waves

Question 17

Acute Heart Failure vs. Chronic Heart Failure

Answer 17

• acute: usually refers to LHF

- chronic: usually refers to L and R HF (AKA congestive heart failure)

Question 18

Signs and Symptoms of LHF

Answer 18

• pulmonary congestion/edema leads to dyspnea, PND, pulmonary crackles

Question 19

Signs and Symptoms of RHF

Answer 19

• peripheral congestion/pitting edema, elevated JVP, nutmeg liver, organomegaly of liver and spleen, ascites