Lecture 2

Question 1

What are the 3 stages of EKG evolution during an acute MI?

Answer 1

1. T wave peaking followed by T wave inversion.
2. ST segment elevation
3. Appearance of new Q waves

Question 2

The 3 stages of EKG evolution during an acute MI should be seen in _____ leads.

Answer 2

2 or more

Question 3

T or F
T wave peaking followed by T wave inversion, ST segment elevation, or the appearance of Q waves can be present without any of the others.

Answer 3

True

Question 4

T waves that become tall and narrow at the onset of the MI

Answer 4

hyperacute T waves

Question 5

hyperacute T waves occur

Answer 5

a few hours after the T waves invert

Question 6

T wave changes reflect _____

Answer 6

ischemia

Question 7

lack of adequate blood flow to the myocardium

Answer 7

ischemia

Question 8

Is ischemia reversible?

Answer 8

yes - if blood flow is restored or oxygen demands of the heart are lessened the T waves will normalize.

Question 9

What happens to the T wave if infarction occurs?

Answer 9

T wave inversion will persist for months to years

Question 10

actual myocardial cell death

Answer 10

infarction

Question 11

ST segment elevation signifies…

Answer 11

injury - cellular damage beyond ischemia

Question 12

Is cellular damage reversible?

Answer 12

yes

Question 13

ST segment elevations is a reliable sign…

Answer 13

an MI has occurred and immediate and aggressive intervention is required.

Question 14

Significant ST elevation

Answer 14

at least 1 mm of ST elevation in two contiguous leads.

Question 15

ST segments usually return to normal post acute MI…

Answer 15

within a few hours

Question 16

Persistent ST segment elevation indicates…

Answer 16

the formation of a ventricular aneurysm.

Question 17

aneurysm

Answer 17

a weakening and bulging of the ventricular wall

Question 18

What is the difference between an MI ST elevation and a Joint elevation?

Answer 18

MI- the elevated ST segment is bowed upward and tends to merge with the T wave.

J point - the T wave maintains its independent wave form.

Question 19

Q waves indicate…

Answer 19

irreversible cell death has occurred.

Question 20

Q waves are diagnostic of…

Answer 20

an MI

Question 21

Q waves appear within ____ of onset of infarction but may take _____ to evolve.

Answer 21

several hours

days

Question 22

ST segment usually has __________ when the Q waves appear.

Answer 22

returned to baseline

Question 23

Q waves stay for how long?

Answer 23

the lifetime of the patient

Question 24

In normal hearts small Q waves can be seen in:

Answer 24

left lateral leads : I, aVL, V5, and V6

and sometimes the inferior leads: II and III

Question 25

Q waves in normal hearts are caused by

Answer 25

left to right depolarization of the intraventricular system.

Question 26

Lead aVR normally has ______ Q wave and _________ has significant Q waves.

Answer 26

a very deep | never

Question 27

Pathologic Q waves are ___________ and ___________ than normal Q waves.

Answer 27

wider and deeper

Question 28

Criteria for significant Q waves

Answer 28

>0.04 sec in duration and depth must be 1/3 the height of the R wave in the same QRS complex

Question 29

mortality rate for non-Q wave MI

Answer 29

These have a lower mortality rate initially but a higher risk for later infarction and mortality than Q wave infarctions.

Question 30

angina that can occur at any time and is usually from coronary artery spasm

Answer 30

Prinzmetal's angina

Question 31

Typical angina is brought on by and is due to:

Answer 31

exertions and is due to progressive atheroclerotic heart disease.

Question 32

ST changes that occur during Prinzmental's angina

Answer 32

ST segment may not have the rounded, domed appearance of an MI, and they will return quickly to baseline when given nitroglycerin

Question 33

Prinzmental's angina occurs in patients with:

Answer 33

underlying CAD or normal coronary arteries.

Question 34

Contraindications to stress testing

Answer 34

``` acute systemic illness severe aortic stenosis Uncontrolled CHF severe HTN angina at rest presence of significant arrhythmia ```

Question 35

How can you test a patient who cannot exercise?

Answer 35

Adenosine stress testing | Dobutamine stress testing