Acute Coronary Syndrome

Question 1

accounts for the vast majority of patients with ischemic heart disease

Answer 1

coronary artery disease

Question 2

predominant symptom of coronary artery disease

Answer 2

chest pain

Question 3

how many % of patients with acute chest pain will have ACS

Answer 3

15%

Question 4

of patients with ACS, approximately __% will have unstable angina

Answer 4

2/3

Question 5

of patients with ACS, ___% will have AMI

Answer 5

1/3

Question 6

rest angina

Answer 6

angina occuring at rest

prolonged, usually > 20 mins

Question 7

new-onset angina

Answer 7

new-onset angina limits ordinary physical activity, such as walking 1-2 blocks;clibing 1 flight of stairs of performing lighter activity

Question 8

increasing angina

Answer 8

previously diagnosed angina that has become distinctly more frequent, has longer duration; lower in threshold, limiting ability to walk 1-2 blocks or climb 1 flight of stairs of perform lighter activity

Question 9

the left coronary artery divides into

Answer 9

left circumflex and left anterior descending branches

Question 10

provides the main blood suply to the anterior and septal regions of the heart

Answer 10

left anterior descending branch

Question 11

the circumflex branch supplies

Answer 11

some of the anterior wall and a lage portion of the lateral wall of the heart

Question 12

the right coronary artery suplies

Answer 12

right side of the heart and perfusion to the inferior aspect of the left ventricle (through its continuation as the right posterior descending artery)

Question 13

atrioventricular conduction system receives blood supply from

Answer 13

a. atrioventricular branch of the right coronary artery

b. septal perforating branch of left anterior descending coronary artery

Question 14

posteromedial papillary muscle receives blood supply from

Answer 14

one coronary artery

usually right coronary artery

Question 15

ischemia occurs when there is an imbalance between

Answer 15

O2 demand

and O2 supply

Question 16

O2 supply is influence by

Answer 16

O2 carrying capacity of the blood

coronary artery blood flow

Question 17

O2 carrying capacity of the blood is determined by the

Answer 17

1. amount of hemoglobin present

2. O2 saturation

Question 18

coronary artery blood flow is determined by

Answer 18

duration of diastolic relaxation of the heart

and peripheral vascular resistance

Question 19

exercise-induced myocardial ischemia usually occur as a result of

Answer 19

fixed atherosclerotic lesions

Question 20

ACS may be caused by

Answer 20

1. secondary reduction in myocardial blood flow due to coronary arterial vasospasm
2. disruption or erosion of atherosclerotic plaques
3. platelet aggregation or thrombus formation at the site of an atherosclerotic lesion

Question 21

secondary causes of myocardial ischemia are

Answer 21

1. increased myocardial O2 demand ( fever, tachycardia, thyrotoxicosis)
2. reduced blood flow ( hypotension)
3. reduced O2 delivery (anemia, hypoxemia)

Question 22

atherosclerotic plauqe forms through

Answer 22

repetitive injury to the vessel wal

Question 23

main cellular elements in plaque development

Answer 23

smooth muscle cells

macrophages

Question 24

predominant extracellular milleu of atherosclerotic plaques

Answer 24

lipids

Question 25

plaque fissuring and rupture are affected by

Answer 25

composition and shape
shear forces
coronary arterial tone
coronary arterial perfusion pressure
movements of the artery in response to myocardial contractions

Question 26

when plaque rupture occurs

what is released

Answer 26

potent thrombogenic substances that activate circulating platelets

Question 27

platelet response involves

Answer 27

adhesion
activation
aggregation

Question 28

platelet interactions with subendothelial adhesion molecular such as collagen, fibronectin, and laminin

binding of the glycoprotein IIb receptor to the subendothelial form of von Willebrand factor

Answer 28

Adhesion

Question 29

release a tissue factor, which stimulates the conversion of prothrombin to thrombin

Answer 29

lipid-laden macrophages

Question 30

platelet activators

Answer 30

thrombin
local shear forces

platelet secretin - adenosine diphoshate, thromboxane A2, serotonin - autostimulatory agonists of platelet activation

Question 31

in the final common pathway of platelet aggregation this occurs

Answer 31

activated platelet glycoprotein IIb/IIIa receptors become cross-linked by
fibrinogen and von Willebrand factor

Question 32

TIMI score for unstable angina includes

Answer 32

age 65 yr or older
3 or more traditional risk factors for coronary artery disease
prior coronary stenosis of 50% or more
ST segment deviation on presenting electrocardiogram
2 or more anginal events prior to 24 h
aspiin use within the 7 day prior to presentation
elevated cardiac markers

Question 33

high likelihood of ACS history

Answer 33

1. chest or left arm pain or discomfort

2. known history of coronary artery disease including myocardial infarction

Question 34

examination of ACS

Answer 34

transient mitral regurgitation murmur

hypotension, diaphoresis, pulmonary edema, rales

Question 35

ECG

Answer 35

new or presumably new, transient ST segment deviation
(>/= 1 mm)

or T wave inversion in multiple precordial leads

Question 36

cardiac markers

Answer 36

elevated cardiac troponin I, troponin T or MB fraction of creatinine kinase