Lab 9

Question 1

what is Ischemic Heart Disease

Answer 1

-known as cornary artery diese which affwcts the supply of blood to the heart
- blood vessels are narrowed or blocked which reduses the blood supply and the oxygen supply to the heart muscles
- could result in death

Question 2

Causes of Ischemic heart disease

Answer 2

smoking, hypertension, high blood LDL, diabetes

Question 3

Diagnosing ischemic heart disease

Answer 3

• affects the muslce cells in endocardium causing hypoxia and weak ventricular depolarization, changes the ST segment on the ECG
• ischemia causes ST segment depression

Question 4

Non transmural myocardial infarction

Answer 4

to a myocardial infarction that does not involve the full thickness of the myocardium

Question 5

What are the types of ST segment depression

Answer 5

downsloping, upsloping, and horiztontal

Question 6

What does horizontal or downsloping St indicate?

Answer 6

myocardial ischemia

Question 7

What does the presence of ST segment elevation indicate

Answer 7

diagonistc of a myocardial infarction

Question 8

What happens in a ST segmental elevation and why?

Answer 8

lack of oxygen delivery through the entire wall of the heart referred to transmural myocardial infarction
- not enoght ATP for the Sodium potassium atpase oump to re-establish the concentration gradient

Question 9

If the ST segment elevation is present in leads 2,3 and AVF which area is the coronary artery impacted?

Answer 9

Inferior wall infraction

Question 10

If the ST segment elevation is present in leads V1, V2, V3, V4 which area is the coronary artery impacted?

Answer 10

Anterior Wall infraction

Question 11

If the ST segment elevation is present in leads 1, avL;, V5, V6 which area is the coronary artery impacted?

Answer 11

Lateral Wall Infraction

Question 12

Both the Anterior and Lateral Leads

Answer 12

Anterolateral Wall Infraction

Question 13

ST segment depression in diagnosing heart disease

Answer 13

amount of ST Segment Depression that would be interpreted as a positive test is 2 mm. The 2 mm is not anarbitrary number; but based upon maximizing sensitivity and
specificity.

Question 14

Sensitivity and how do you calculate it

Answer 14

The percent of individuals with heart disease that testpositive for the disease.
Sensitivity = TP/(TP + FN)
TP = True Positive
FN = False Negative
When using the 2 mm criteria, the Sensitivity is ~80%

Question 15

Specificity and how do you calculate it

Answer 15

The percent of individuals without heart disease that testnegative for the disease.
Specificity = TN/(TN + FP)
TN = True Negative
FP = False Positive

Question 16

Angiography

Answer 16

s a medical imaging
technique where a catheter is directed
to a coronary artery and a radiopaque
substance is injected in order to
visualize the blood vessels

Question 17

Angioplasty

Answer 17

▪ The balloon pushes the plaque outward against the arterial
wall. This widens the artery and restores blood flow.
▪ However, this technique is rarely used since it would result in
the redevelopment of atherosclerosis called restenosis.
▪ Endothelial Injury Hypothesis

Question 18

Stent

Answer 18

When the balloon is inflated, the Stent expands pushing the
plaque outward against the arterial wall.
▪ As before, the artery widens and blood flow is restored.
▪ However, the Stent which remains within the blood vessel is made
of anticoagulant materials which prevents platelet aggregation.
▪ The advantages of using a Stent is the faster recovery time and
the lower risk of complications compared to CABG.

Question 19

Coronary Artery Bypass

Answer 19

nce this blood vessel is obtained, the chest is opened, and
tubes are inserted into the heart so that blood can be directed to
a heart-lung bypass machine. This is necessary so the patient’s
body can still receive oxygenated blood when the heart is
stopped so that the doctor can perform the bypass.
▪ The disadvantages include the higher risk of mortality during the
procedure, the higher cost, and the increased recovery time.