MI & Angina

Question 1

What is the definition of a myocardial infarction?

Answer 1

Occurs when one of the coronary arteries becomes totally occluded, so the region of the heart supplied by that artery loses its blood supply and dies due to lack of oxygen and other nutrients

Question 2

What generally causes the progression to infarction?

Answer 2

Progressive narrowing of the coronary arteries by atherosclerosis with superimposed thrombosis or spasm of the coronary artery

Question 3

What kind of patients commonly present atypically?

Answer 3

Elderly, diabetics, and females may be atypical and up to 1/3 are silent

Question 4

Name the changes in an EKG during an acute MI. Which need to be present together?

Answer 4

http://click.email.thinkgeek.com/?qs=ba1d7a3825e7e48aff7a0979c0dd29ee2e1e7691e2cc16882cad0a1c598cfa0b 1) T wave peaking followed by T wave inversion
2) ST segment elevation
3) Appearance of new Q waves
In 2 or more leads, any can be present without another!
1) T wave peaking followed by T wave inversion
2) ST segment elevation
3) Appearance of new Q waves
In 2 or more leads, any can be present without another!

Question 5

At the onset of the MI how do T waves generally appear?

Answer 5

hyperacute T waves, a few hours later they invert

Question 6

What do T wave changes reflect? Are they reversible?

Answer 6

Reflect ischemia, Reversible if flow restored or oxygen demands decreased

Question 7

If actual cell death (infarction) has occured how long will T wave inversion persist for?

Answer 7

Months to years

Question 8

What is psedunormalization?

Answer 8

Patients who already have inverted T waves, ischemia may cause them to become normal

Question 9

Are ischemic T wave inverted symmetricly or asymmetricly?

Answer 9

symmetrically

Question 10

What does ST segment elevation signify? Is this reversible?

Answer 10

Injury. Still reversible but requires immediate and aggressive intervention

Question 11

How long does it take for ST segments to return to normal?

Answer 11

A few hours

Question 12

Persistent ST segment elevation indicates?

Answer 12

formation of a ventricular aneurysm

Question 13

What is ST segment elevation called in normal healthy hearts?

Answer 13

Early repolarization of J point elevation

Question 14

How does the elevated ST segment of MI look different for the J point elevation?

Answer 14

In J point elevation, the T wave maintains its independent waveform. In MI, ST segment is bowed upward and tends to merge with the T wave.

Question 15

What do Q waves indicate?

Answer 15

Irreversible cell death, are diagnostic of MI

Question 16

When do Q waves form during MI and how long do they stay?

Answer 16

Usually appear several hours after onset of infarction but may take days to evolve. ST segment has usually already returned to baseline. Q waves usually stay for the lifetime of the patient.

Question 17

An electrode overlying the infarct will record a _________ Q wave

Answer 17

Deep negative deflection

Question 18

Electrodes in distant leads to the infarct will record ______ R waves and possible________ ST segments

Answer 18

tall positive R waves and depressed ST segements

Question 19

What lead can not be used to diagnose MI with a Q wave?

Answer 19

aVR, normally has a deep Q wave

Question 20

In normal hearts, small q waves can be seen in what leads?

Answer 20

Left lateral ( I, aVL, V5, V6) and sometimes inferior leads (especially II and III)

Question 21

Significant Q waves must be:

Answer 21

Greater than 0.04 seconds (1 small block) duration and depth of q wave must be atleast 1/3rd height of the R wave

Question 22

Inferior infarcts usually caused by occlusion of the

Answer 22

right coronary artery or its descending branch

Question 23

An 85 year old women presents to the ED with chest pain. Her EKG shows T wave inversion and ST segment elevation. Her troponins are elevated. You quickly send her to cath lab but it is determined she has no coronary artery disease. What is your diagnoses?

Answer 23

Apical Ballooning Sydrome

Question 24

What is typical angina described as?

Answer 24

Dull, burning, or boring substernal pressure or heaviness, typically worse with exertion or stress, relieved by rest and nitroglycerin

Question 25

What EKG changes could be present during angina attack?

Answer 25

ST segment depression or T wave inversion

Question 26

What kind of angina is the result of coronary artery spasm?

Answer 26

Prinzmetal’s Angina

Question 27

What underlying processes make diagnosing an MI harder via EKG?

Answer 27

WPW, LVH, LBBB

Question 28

A positive stress test will show….

Answer 28

ST segment depression

Question 29

True of False: A negative stress test excludes CAD

Answer 29

FALSE

Question 30

If a patient cannot exercise what other kinds of stress tests can be performed?

Answer 30

Adenosine and dobutamine stress testing

Question 31

Occlusion of the left circumflex can lead to what kind of infarct?

Answer 31

Lateral infarction

Question 32

An anterior infarction is usually the result of occlusion from

Answer 32

left anterior descending

Question 33

A posterior infarction is usually a result of an occlusion from

Answer 33

right coronary artery

Question 34

Changes diagnostic of MI in the precoridal leads and reciprical changes in inferior leads is diagnostic of an MI in what location?

Answer 34

Anterior Infarct

Question 35

Changes diagnostic of MI in the leads II, III, and aVF with reciprical changes V1, I, aVL, V5, and V6 is diagnostic of an MI in what location?

Answer 35

Inferior Infarct