ECG Information

Question 1

How long should be PR interval be?

Answer 1

.12-.2 seconds

(3-5 small squares)

Question 2

How long should the QRS complex be?

Answer 2

0.05- 0.1 seconds

Question 3

QRS complex longer than .12

Answer 3

Bundle branch block

Ventricular hypertrophy

Question 4

Q wave should be how long?

Answer 4

0.03 (about 1 small square wide)

or 1/3 tall of the entire QRS complex

Question 5

QT interval should be how long?

Answer 5

From the begining of the QRS–> end of T

0.35 seconds

Question 6

A short PR interval indicates what?

Answer 6

1. WBW dz
2. Levines
3. Glycogen storing dz
4. HTN
5. Junctional/nodal rhythms

Question 7

A long PR interval can indicate?

Answer 7

1. AV block (because this is the time it takes to get from the SA node through the AV node)
2. Hyperthyroidism

Question 8

During diastole, what is happening

Answer 8

Ventricle relaxing

Atria contracting

Question 9

During systole, what is happening?

Answer 9

Ventricle is contracting

Atria is relaxing

Question 10

Stages of cardiac cycle

Answer 10

1. Atrial systole
2. Isvolumetric ventricular contraction
3. Ventricular ejection
4. Isovolumetric ventricular relaxation

Question 11

What stages in cardiac cyle are we in during QRS?

Answer 11

1. Atrial systole
2. Isovolumetric ventricular contraction

Question 12

Why are we in isovolumetric relaxation during the last part of T wave?

Answer 12

Because our cells that are the 1st to depolarize are the last to repolarize

Question 13

End of QRS interval begins what?

Answer 13

Ventricular ejection

Question 14

How do we find the degree of axis?

Answer 14

1. Find the area that the QRS wave cancels out.
2. Go to the axis of deviation and find the one that is perpendicular

Question 15

Movement of ST segment tells us what?

Answer 15

ventricular myocytes are not depolarizing at the same time and we cannot reach an isoelectric point

Question 16

ST depression

Answer 16

subendocardial infarction

Question 17

ST elecation

Answer 17

subepicardial or transmiral ischemia

Question 18

What represeents the length of ventricular systole on ECG?

Answer 18

QT interval

Question 19

QT interval can tell us what?

Answer 19

1. Mycardial ischemia (T wave)
2. Myocardiac injury (ST segment)
3. Myocardial infarction (Q wave)

Question 20

PR segment tells us what

Answer 20

Time to go from AV node–> ventricles

Question 21

If P wave occurs after QRS?

Answer 21

1. SVT

2. Junctional rhythm

3. Change side of pacemaker

Question 22

Why is repolarization upward deflected?

Answer 22

It moves away from the lead

Question 23

QRS assignments

Answer 23

Q- first negative defletion BEFORE R

R- first upward deflection

S- negative deflection after the R

Question 24

What do we use on the ECG to tell us heart rate and rhythm?

Answer 24

Rhythmic lead II at the bottom

Question 25

When we describe an area of infarct, what part of the heart are we referring to?

Answer 25

LV

Question 26

Injury--\>

Answer 26

elevated ST

Question 27

Infarction

Answer 27

Deep and wide Q, more than 1 square wide

Question 28

Anginga

Answer 28

only an inverted T wave

Question 29

How to find a STEMI

Answer 29

Look at all the leads except aVR. 1. Look for a deep Q wave 2. Look at the ST segment to tell us if acute or not. It is the first sign of an MI and returns to baseline with time. 3. Look for an inverted T wave

Question 30

How can we spot the difference between a anterior and posterior acute MI? Subendocardial infarction?

Answer 30

Anterior acute MI- a significant Q wave and a ST elevation in V1 and V2 - Posterior acute MI would have the opposite effects because they depolarize in opposite directions - Large R wave in V1 and V2 - ST depression -----if only ST depression--\> **subendocardial infarction** -

Question 31

1 AV block

Answer 31

Delay between the atrial and ventricular depolarization is lengthened (PR interval= \>/2 seconds) remains consistently prolonged

Question 32

2 AV block

Answer 32

Some P waves send signals to ventricles, while smoe atrial depolariations are blocked, leacing long P waves without a QRS 2 types Type 1--\> Wenckenback Type 2--\> Morbitz

Question 33

Type 1 2 AV Block

Answer 33

QRS looks normal One less QRS than P wave because the PR interval lengthns but last one does not go to ventricle

Question 34

Type 2 2 AV block (morbitz)

Answer 34

3: 1 4: 1 5: 1

Question 35

How to determine what kind of block

Answer 35

1. Look at PR interval: is it long and stay the same length? Yes--\> 1 degree Gets longer? Yes--.\> 2 degree