Peripheral Vascular System & Ischemia Part 2 Flashcards Preview

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Flashcards in Peripheral Vascular System & Ischemia Part 2 Deck (33):
1

What occurs when one of the coronary arteries becomes totally occluded?

Myocardial Infarction

2

What may cause an MI? (6)

Occlusion – thrombosis
Coronary artery spasm – smooth muscle constriction
Decreased coronary artery blood flow
Increased myocardial workload
Decreased O2 levels
Toxic exposure to cocaine and ethanol

3

What are some signs when diagnosing an MI?

Prolonged substernal chest pain with radiation of pain to jaw or left arm (>30min), nausea, diaphoresis, and shortness of breath

Or, pt can have a "Silent MI"

 

4

What cardiac enzymes are affected in an MI? (3)

Troponin I: rise early and stay elevated for days*
CK-MB: 6 hours to rise and then normalize in 48 hours
CK

5

KNOW

What ECG changes when diagnosing an MI? (3)

T wave changes: first peak then inversion
ST segment elevation/depression: usually elevation with MI
Q waves: indicate irreversible myocardial cell death

6

What is the first enzyme indicator of a MI? How long will it remain elevated?

troponin

5-7 days

7

What cardiac enzyme will be elevated within 6 hours?

CK-MB

8

What are the stages of an AMI? (Acute MI) 

(4)

T wave peaking
ST segment elevation
Appearance of new Q waves
T wave inversion

A image thumb
9

What is occuring with this waveform?

Q image thumb

ISCHEMIA

Note: T wave inversion is not diagnostic of MI. If true infarct occurs – inversion can persist for months to years.

 

10

What part of the ECG reflects myocardial injury?

ST segment elevation

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11

Is ST segment elevation reversible?

Yes, may reflect some damage, but still reversible and can return to normal.

12

What is a type of ST segment elevation seen in normal hearts?

 

J Point – where the ST segment takes off from the QRS complex

 

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13

How do you distinguish a J point from MI? (2)

T wave maintains its independent waveform

In MI, elevation is bowed upward and tends to merge with T wave

14

Over ___ mm of ST segment elevation is clinically significant.

1

15

What ECG wave indicates irreversible myocardial death, is diagnostic of MI, usually appears within hours of infarct, and is persistent for a lifetime?

Q waves

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16

During an infarction, ST segment usually goes back to baseline by the time Q waves appear.  True or false?

True

17

Q wave > ____ sec in duration and depth at least ___ height of R wave signifies MI.

0.04

1/3

18

In leads distant from the site of infarction, will see these ECG changes: (2)

Tall R waves
ST segment depression 

19

What artery supplies the anterior portion of the heart and most of the interventricular septum?

LAD

20

What part of the heart does the LAD supply?

supplies the lateral wall of the left ventricle

21

What is caused by occlusion of right coronary artery or descending branch of left coronary artery?

What leads will show changes?

inferior infarcts

II, III, AVF

 

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22

Reciprocal changes will be seen in these leads in inferior infarcts: (2)

anterior

lateral leads

Note: also will observed peaked R waves.

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23

For lateral wall infarcts, will observe changes in what leads? (4)

Note: you will also see reciprocal changes in inferior leads.

I

AVL

V5

V6

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24

What type of MI is caused by the occlusion of the left circumflex?

lateral wall infarct

25

What is caused by an occlusion of the left anterior descending artery?

anterior wall MI

26

In what leads will a left anterior descending infarct be apparent?

Q image thumb

V1-V6

There will be reciprocal changes in the inferior leads.

27

What results from the occlusion of the right coronary artery?

posterior wall MI

28

For what type of MI do the leads not overly and you have to look for reciprocal changes in the anterior leads?

posterior wall MI

29

What will you notice in a posterior wall MI, or occlusion of the right coronary artery?

ST segment depression and tall R waves, especially in V1

30

What type of MI has a higher risk of later infarction and mortality?

Non Q wave MI

Note: It will behave like small, incomplete infarctions.

31

What is angina/ischemia characterized by? (3)

EKG is often normal

ST segment depression

T wave inversion

32

If patient already has a condition that affects the ST segment and QRS, it makes diagnosis of an infarct impossible.  True or false?

true

33

What syndromes make the diagnosis made by an EKG unreliable? (2)

LBBB

WPW