CH3 The Electrocardiograph

Question 1

How many wires are used on a 12-lead EKG

Answer 1

10

Question 2

Leads

Answer 2

Covered wires that conduct the electrical impulse from the electrodes to the ECG machine

Question 3

Electrodes

Answer 3

Small sensors placed on the skin to detect the electrical activity from the heart

Question 4

Einthoven’s triangle

Answer 4

A triangle formed by 3 of the limb electrodes, the right arm, left arm, and left leg

Question 5

Limb lead

Answer 5

An ECG lead placed on an arm or leg

Question 6

Bipolar lead

Answer 6

A type of ECG lead that measures the flow of electrical current in both directions at the same time

Question 7

Lead I

Answer 7

Right arm to left arm
Bipolar

Question 8

Lead II

Answer 8

Right Arm to Left leg
Bipolar

Question 9

Lead III

Answer 9

Left arm to Left Leg
Bipolar

Question 10

Augmented leads

Answer 10

Normally small ECG lead tracing that are increases in size by the ECG machine in order to be interpreted

Question 11

Unipolar leads

Answer 11

A type of ECG lead that measures the flow of electrical current in 1 direction only

Question 12

aVR

Answer 12

Lead measures from heart to the right arm
Augmented unipolar lead
Usually negative deflection

Question 13

aVL

Answer 13

Heart to Left arm
Augmented unipolar lead

Question 14

aVF

Answer 14

Heart to Left leg
Augmented unipolar lead

Question 15

Precordial lead

Answer 15

A type of lead placed on the chest in front of the heart;
Known as a V lead

Question 16

V1 placement

Answer 16

Right sternum
4th intercostal space

Question 17

V2 placement

Answer 17

Left sternum
4th intercostal space

Question 18

V3 placement

Answer 18

Midway btw V2 and V4

Question 19

V4 placement

Answer 19

Midclavicular line
5th intercostal space

Question 20

V5 placement

Answer 20

In line with V4 At anterior axillary line

Question 21

V6 placement

Answer 21

In line with V4 AND V5 at the mid-axillary line

Question 22

Multichannel recorder

Answer 22

an ECG machine that monitors all 12 leads but records 3 leads at a time and switches leads automatically, recording each of the 4 sets of 3 leads

Can also be read in 2 sets of 6 leads

Question 23

Input

Answer 23

Data entered into an ECG machine, usually through electrodes on the skin surface

Question 24

Signal Processing

Answer 24

The process within the ECG machine that amplifies the electrical impulse and converts it to a mechanical action on the output display

Question 25

Output display

Answer 25

The part of⁰ the ECG machine that displays the tracing for the electrical activity of the heart, usually inban electronic or printed form on a 12-lead machine

Question 26

3 basic functions of an ECG

Answer 26

Input, signal processing, output display

Question 27

Speed control

Answer 27

A control on the ECG machine that regulates how fast or slow the paper runs during the tracing

Question 28

In what cause would you increase speed to 50 mm/sec

Answer 28

If patient has unusually rapid heart rate

Question 29

Gain

Answer 29

A control on the ECG machine that increases or decreases the size of the deflections on the ECG tracing

Question 30

Normal gain setting for an ECG

Answer 30

10 mm/mV

Question 31

What happens if you set gain to 20mm/mV

Answer 31

The waveform gets taller

Question 32

Artifact

Answer 32

Unwanted marks on the ECG tracing causes by activity other than the hearts electrical activity

Question 33

Normal setting for hertz on an ECG

Answer 33

40-50 Hz

Question 34

What does a lead selector do

Answer 34

Allows you to run each lead individually

Question 35

1mm equals how many secs in 25mm/sec ECG tracing?

Answer 35

0.04 secs

Question 36

1 mm on a 10mm/mV tracing?

Answer 36

0.01 mV

Question 37

300 method

Answer 37

Count large boxes from R to R
Calculate 300 ÷ (#large boxes)

Question 38

1500 method

Answer 38

Count # small boxes
Calculate 1500 ÷ (#small boxes)

Question 39

6-second method

Answer 39

Identify 6-sec section of tracing
Count # complete complexes seen in 1 6-sec interval
Multiply # of complexes by 10