EKG

Question 1

1 small box?

Answer 1

1 mm = 0.04 seconds, 1 mV

Question 2

1 large box?

Answer 2

5 mm = 0.2 seconds, 5 mV

Question 3

Normal sinus rhythm?

Answer 3

Rate 60-100
P waves identifiable and of the same morphology throughout

RR intervals between beats are the same

Question 4

Normal duration of P wave?

Answer 4

No more than 1 box wide

Question 5

Normal voltage of P wave?

Answer 5

No more than 1 box tall

Question 6

Best lead to look at P wave?

Answer 6

V1

Question 7

If P wave exceeds the normal range for duration or voltage, what does this mean?

Answer 7

Either or both atria are hypertrophied

Question 8

Q wave?

Answer 8

First downstroke (usually very small or absent)

Question 9

R wave?

Answer 9

First upward deflection

Question 10

S wave?

Answer 10

First downward deflection after the R wave

Question 11

Normal QRS complex duration?

Answer 11

0.08-0.12 seconds

Question 12

Prolonged QRS complex?

Answer 12

BBB
Drug toxicity
Electrolyte imbalance

Question 13

Shortened QRS complex?

Answer 13

WPW

Question 14

Q wave can be normal in what 2 leads?

Answer 14

III and aVR

Question 15

When is a Q wave significant?

Answer 15

> 1 box wide in any lead except III and aVR
1/3 the amplitude of QRS
1/4 R wave

Indicates infarct

Question 16

What is the normal direction and amplitude of T waves?

Answer 16

In general, T waves are in the same direction as the largest deflection of the QRS (normally the R wave)

Negative in aVR
Negative in V1, V2, V3 can be seen in normal young athletes

Question 17

Primary T wave change?

Answer 17

Abnormal repolarization

Question 18

Secondary T wave change?

Answer 18

Caused by QRS changes (BBB, hypertrophy)

Question 19

Tall peaked T waves?

Answer 19

Hyperkalemia

Question 20

Low voltage T waves and prominant U waves?

Answer 20

Hypokalemia

Question 21

Inverted T waves?

Answer 21

Coronary ischemia

Question 22

Normal PR interval?

Answer 22

0.12-2.0 seconds

Question 23

Prolonged PR interval?

Answer 23

AV block

Question 24

Define 1st degree AV block

Answer 24

PR >0.2 seconds`

Question 25

Define 2nd degree AV block Type I

Answer 25

Mobitz I/Wenckeback Increasing PR interval until QRS dropped, usually benign

Question 26

Define 2nd degree AV block Type II

Answer 26

Mobitz II QRS dropped without any progressive increase in PRinterval

Question 27

Define 3rd degree AV block

Answer 27

P waves and QRS complexes occur independently of each other

Question 28

Shortened PR interval?

Answer 28

<0.12 WPW when associated with prolonged QRS

Question 29

Calculate QTc

Answer 29

= QT + 1.75(ventricular rate - 60)

Question 30

Normal QTc?

Answer 30

~0.41 seconds

Question 31

Prolonged QTc?

Answer 31

Hypocalcemia