Lab 9 Flashcards
what is Ischemic Heart Disease
-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
Causes of Ischemic heart disease
smoking, hypertension, high blood LDL, diabetes
Diagnosing ischemic heart disease
- affects the muslce cells in endocardium causing hypoxia and weak ventricular depolarization, changes the ST segment on the ECG
- ischemia causes ST segment depression
Non transmural myocardial infarction
to a myocardial infarction that does not involve the full thickness of the myocardium
What are the types of ST segment depression
downsloping, upsloping, and horiztontal
What does horizontal or downsloping St indicate?
myocardial ischemia
What does the presence of ST segment elevation indicate
diagonistc of a myocardial infarction
What happens in a ST segmental elevation and why?
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
If the ST segment elevation is present in leads 2,3 and AVF which area is the coronary artery impacted?
Inferior wall infraction
If the ST segment elevation is present in leads V1, V2, V3, V4 which area is the coronary artery impacted?
Anterior Wall infraction
If the ST segment elevation is present in leads 1, avL;, V5, V6 which area is the coronary artery impacted?
Lateral Wall Infraction
Both the Anterior and Lateral Leads
Anterolateral Wall Infraction
ST segment depression in diagnosing heart disease
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.
Sensitivity and how do you calculate it
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%
Specificity and how do you calculate it
The percent of individuals without heart disease that testnegative for the disease.
Specificity = TN/(TN + FP)
TN = True Negative
FP = False Positive
Angiography
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
Angioplasty
▪ 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
Stent
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.
Coronary Artery Bypass
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.
