6: EKG Waveforms

Question 1

Vertical axis of an EKG is _____.

Answer 1

Vertical axis of an EKG is voltage in millivolts (mV).

Question 2

Horizontal axis of an EKG is _____.

Answer 2

Horizontal axis of an EKG is time in milliseconds (msec).

Question 3

Each small box of an EKG represents _____.

Answer 3

Each small box of an EKG represents 0.04 seconds.

Question 4

Each large box of an EKG represents _____.

Answer 4

Each large box of an EKG represents 0.20 seconds.

Question 5

5 large boxes of an EKG represents _____.

Answer 5

5 large boxes of an EKG represents 1 second.

Question 6

We measure an impulse traveling between a _____ and a _____ electrode.

Answer 6

We measure an impulse traveling between a positive and a negative electrode.

Question 7

Impulse moving towards positive electrode = _____ deflection on graph.

Answer 7

Impulse moving towards positive electrode = positive deflection on graph.

Question 8

Impulse moving towards negative electrode = _____ deflection on graph.

Answer 8

Impulse moving towards negative electrode = negative deflection on graph.

Question 9

The more directly an impulse heads toward a positive lead, the _____ it will be on the graph.

Answer 9

The more directly an impulse heads toward a positive lead, the higher it will be on the graph.

Question 10

The more directly an impulse heads away from a positive lead, the _____ it will be on the graph.

Answer 10

The more directly an impulse heads away from a positive lead, the lower (more negative) it will be on the graph.

Question 11

T/F EKGs can diagnose arrhythmias and other cardiac abnormalities.

Answer 11

False. An EGK can only diagnose arrhythmias, though it can suggest other abnormalities.

Question 12

What is the sequence of how the standard measurements of an EKG are written?

Answer 12

PR/QRS/QT

.12/.08/.40 for example

Question 13

Represents time it takes for an impulse to spread through the atria, AV node, and bundle of His.

Answer 13

PR Interval

Question 14

From beginning of P wave to beginning of QRS complex.

Answer 14

PR Interval

Question 15

Normal PR Interval.

Answer 15

0.12-0.20 seconds (3-5 small squares)

Question 16

Starts with deflection away from PR interval, continues to end of QRS complex (J point).

Answer 16

QRS Interval

Question 17

Represents the time taken for an impulse to spread down the bundle branches and Purkinje fibers through the ventricles

Answer 17

QRS Interval

Question 18

Normal QRS Interval.

Answer 18

0.04-0.12 (1-3 small squares)

Question 19

T/F Every QRS complex must have a Q, R, and S wave.

Answer 19

False

Question 20

The initial negative deflection in the QRS Interval.

Answer 20

Q Wave

Question 21

The first positive deflection in a QRS Interval.

Answer 21

R Wave

Question 22

Any subsequent negative deflection in a QRS Interval.

Answer 22

S Wave

Question 23

Represents the entire time taken for electrical depolarization and repolarization of the ventricles.

Answer 23

QT Interval

Question 24

Starts at the beginning of the QRS complex (same as the end point for PR) and continues to the end of the T wave.

Answer 24

QT Interval

Question 25

The QTc (or QT corrected) corrects QT interval for _____.

Answer 25

The QTc (or QT corrected) corrects QT interval for heart rate.

Question 26

T/F Fluctuation of heart rate makes comparison of one QT to another useless; QTc corrects for these changes.

Answer 26

True

Question 27

The _____ the heart rate, the shorter the QT Interval.

Answer 27

The faster the heart rate, the shorter the QT Interval.

Question 28

Normal QT Interval.

Answer 28

Less than 0.44 seconds (less than approximately 2.5 large boxes).

Question 29

Represents depolarization of the atria (which hopefully leads to contraction of the atria).

Answer 29

P Wave

Question 30

Represents depolarization of the ventricles (which hopefully leads to ventricular contraction).

Answer 30

QRS Complex

Question 31

Represents repolarization of the ventricles.

Answer 31

T Wave

Question 32

T/F Repolarization of the atria is not seen on an EKG.

Answer 32

True. It either happens during the QRS Complex or the voltage is so little it does not show up.

Question 33

Represents absolute refractory period.

Answer 33

End of QRS Complex to the beginning of T Wave

Question 34

Represents relative refractory period.

Answer 34

Part of T Wave to beginning of new P Wave

Question 35

The period immediately following the firing of a nerve fiber where it cannot be stimulated no matter how great a stimulus is applied.

Answer 35

Absolute Refractory Period

Question 36

A stronger than normal stimulus is needed to elicit nueronal excitation.

Answer 36

Relative Refractory Period

Question 37

Cardiac pathway of electrical impulse.

Answer 37

Sinus Node - Internodal Pathways - AV Node - Bundle of His - Left and Right Bundle Branches - Purkinje Fibers

Question 38

Falls between the QRS Complex and T Wave.

Answer 38

ST Segment

Question 39

These, if present, are often confused with P Waves.

Answer 39

U Wave

Question 40

Thought to represent repolarization of the Purkinje fibers.

Answer 40

U Wave

Question 41

A slurred upstroke in the QRS complex often associated with a short PR Interval.

Answer 41

Delta Wave