Ischemic heart diseases

Question 1

What is ischemia?

Answer 1

Reversible lack of perfusion of tissue

Question 2

What is ischemic heart disease?

Answer 2

Not enough O2 to meet demands but enough to keep tissue viable

Question 3

Ischemia is a result of?

Answer 3

Stenosing of a blood vessel;

Atherosclerosis ( coronary artery disease)

Question 4

What is an infarction ?

Answer 4

Irreversible lack of perfusion of tissue leads to tissue necrosis

Question 5

Describe the tissue changes in an infarction.

Answer 5

1. First 24 hours - No macroscopic or microscopic change.
2. 24 – 48 hours - Pale / eosinophilic / (neutrophils) at edge
3. Days to weeks - Macrophages remove dead tissue (Granuloma)
4. Months - Fibrosis, scar tissue

Question 6

Causes of a Low-flow infarction

Answer 6

Arterial stenosis or spasm

Question 7

Presentation of CAD

Answer 7

a. Asymptomatic: subclinical stenosis
b. Angina Pectoris: obstructive lesion lead to ischemia at effort
c. Acute Coronary Syndrome: plaque ruptured

Question 8

Categories of Symptomatic CAD

Answer 8

Stable angina

Acute coronary syndrome

Question 9

Acute Coronary syndrome differential diagnosis and its features in terms of ECGs and serum markers

Answer 9

a. Unstable Angina: no ST elevation + no serum markers
b. NSTEMI: no ST elevation + serum markers
c. STEMI : ST elevation + serum markers

Question 10

Non-thrombo-embolic vascular insufficiency Dx

Answer 10

a. Athersclerosis
b. Vasospasm
c. External Compression
d. Steal Syndromes
e. Increased blood viscosit

Question 11

The fate of a thrombus

Answer 11

Resolution /
 Organising / 
Recanalise /
 Death / 
embolise

Question 12

Causes of Thrombo-embolic vascular occlusion

Answer 12

Virchows Triad :

1. Endothelial damage
2. stasis
3. hypercoagulability

Question 13

Describe the events leading to an atheroma formation in sequence

Answer 13

a. Endothelial Dysfunction: leads to remodelling of artery & lymphocyte infiltration
b. Fatty Streaks: foam cells beneath endothelium T.Intima
c. Plaque Formation: foam cells covered by fibrous collagen cap (muscle)
d. Plaque Growth: expansion of stenosis due to inflammation
e. Platelet activation: collagen exposure leads to platelet activation
f. Plaque rupture: large amounts of clotting which could lead to occlusion
g. Coronary Artery Thrombus : thrombus leading to malperfusion of cardiac tissue

Question 14

TIMI SCORE criteria

Answer 14

a. Age > 65
b. Markers (increased serum cardiac markers)
c. EKG (ST depression)
d. Risk factors (3 or more CAD risk factors)
e. Ischemia (2 or more anginal events over past 24 hours)
f. CAD (prior coronary stenosis of 50% or more)
g. Aspirin use within past 7 days