Ch. 3 Key Terms

Question 1

Artifact

Answer 1

Unwanted marks on the ECG tracing caused by activity other than the heart’s electrical activity

Question 2

Augmented lead

Answer 2

Normally small ECG lead tracings that are increased in size by the ECG machine in order to be interpreted

Question 3

Bipolar lead

Answer 3

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

Question 4

Bradycardia

Answer 4

Slow heart rate; less than 60 bpm

Question 5

Einthoven triangle

Answer 5

Triangle formed by three of the limb electrodes: left arm, right arm, and left leg; used as a reference for the first 6 leads of the 12-lead ECG

Question 6

Electrodes

Answer 6

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

Question 7

Gain (sensitivity)

Answer 7

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

Question 8

Hertz (Hz)

Answer 8

Unit of frequency measured in cycles (or events) per second

Question 9

Input

Answer 9

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

Question 10

Lead

Answer 10

Direction in which the heart’s electrical activity is viewed or determined

Question 11

Lead wires

Answer 11

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

Question 12

Limb lead

Answer 12

ECG placed on an arm or a leg

Question 13

Millimeter (mm)

Answer 13

Unit of measurement to indicate time on the tracing period
Time is measured on the horizontal axis

Question 14

Millivolt (mV)

Answer 14

Unit of measurement to indicate voltage on an ECG tracing
Voltage is measured on the vertical axis

Question 15

Multichannel recorder

Answer 15

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

Question 16

Output display

Answer 16

Part of ECG machine that displays the tracing for the electrical activity of the heart, usually in an electronic or printed form on a 12-lead ECG machine

Question 17

Precordial lead

Answer 17

Type of lead placed on the chest in front of the heart; aka V lead

Question 18

Serial ECG comparison

Answer 18

Multiple and frequent ECG tracings recorded at intervals based upon the patient’s condition and compared to identify changes

Question 19

Signal processing

Answer 19

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

Question 20

Speed control

Answer 20

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

Question 21

Tachycardia

Answer 21

Rapid heart rate; more than 100 bpm

Question 22

Unipolar lead

Answer 22

Type of ECG that measures the flow of electrical current in one direction only