Chapter 3: EKG

the einthoven triangle is formed by the following three limb leads

right arm, left arm, left leg

which of the following is NOT a type of lead used in a 12-lead ECG

a. unipolar (precordial)

b. chest

c. abdomen

d. bipolar

c. abdomen

which of the following is NOT considered a bipolar lead

a. aVR

b. lead I

c. lead III

d. lead II

a. aVR

the V1 lead should be placed at the

fourth intercostal space, right sternal border

for the proper placement of V3, you must have placed which two other leads on the patient’s chest

V2 and V4

unipolar leads include all of the lead types except

standard leads

to obtain a 12-lead ECG tracing, you must apply how many lead wires and electrodes to the patient

10

the V2 lead should be placed at the

fourth intercostal space, left sternal border

the leads that make up a 12-lead ECG consist of

3 standard, 3 augmented, 6 chest leads

which of the following is NOT a basic function of the electrocardiograph

a. output display

b. signal processing

c. analysis

d. input

c. analysis

signal processing, which occurs inside the ECG machine,

amplifies the electrical impulse

the most commonly used paper speed on the ECG machine is

25 mm/sec

the gain control is normally set at

10 mm/mV

often it is difficult to read the ECG training if a patient’s heart rate is fast. where should you set the speed control to be able to interpret the ECG tracing more easily

50 mm/sec

the usual setting for the artifact filter is

40 to 150 Hz

you are preparing to conduct a 12-lead ECG on a patient. as you are gathering your supplies, you notice that 5 of the electrodes are made by one company and the other 5 electrodes are made by another company. what is your next step

find a complete set of 10 electrodes that are the same

which type of electrode is preferred for use in a hospital or acute care setting

silver electrodes

the ECG graph paper represents time horizontally and voltage vertically. what time and voltage are represented by one large box

0.2 sec/0.5mV

you are performing a 12-lead ECG on a hospital patient using a portable ECG machine on a cart. as you are conducting the ECG, a red line appears at the bottom of the ECG graph paper. what should you do

continue the ECG, but remember to replace the paper before performing the next ECG

each little box on the ECG paper horizontally represents

0.04 second

which of the following is an advantage of using dot matrix paper instead of the standard grid paper

a. dot matrix paper is less expensive than standard grid paper

b. dot matrix paper is a heat-transfer paper that does not require ink

c. dot matrix paper produces sharper photocopies than standard grid paper

d. dot matrix paper is more readily available than standard grid paper

c. dot matrix paper produces sharper photocopies than standard grid paper

which of the following substances can accidentally erase an ECG tracing

a. plastic

b. pencil lead

c. standard copier paper

d. cardboard

a. plastic

when the paper speed is 25 mm/sec, how many boxes are present in a 1-minute recording

300 boxes per minute

which one of these is NOT a commonly used method to calculate heart rates

a. 1500 method

b. 6-second method

c. 1-minute method

d. R-R method

c. 1-minute method

which method is the ONLY one to be used for irregular rhythms

6-second method

when estimating the heart rate with the 6-second method, you locate 6 seconds on a rhythm strip, count the number of complexes and multiply by

10

which method of calculating the heart rate is shown below

a. 1-minute method

b. R-R method

c. 1500 method

d. 6-second method

c. 1500 method

which heart rate method is the most accurate with regular rhythms

a. 1500 method

b. 300 method

c. 6-second method

d. R-R method

a. 1500 method

to perform an ECG with accuracy, the best source to obtain specific information about the machine you are using is to consult

the manufacturer’s instructions

computerized interpretation of the ECG tracing

must be validated by a physician

a multi channel ECG monitors all 12 leads but usually records how many leads at one time

3 leads

which of the following is a valid reason to change the speed of the ECG tracing

a. the patient is a paramedic and requests a different speed

b. the patient is having difficulty breathing

c. the patient has high blood pressure

d. you cannot clearly identify the waves because they are too close together

d. you cannot clearly identify the waves because they are too close together

if you attempt to record an ECG and no tracing appears, what should you do

recheck the lead wires to make sure they are placed correctly

bradycardia

slow heart rate

tachycardia

fast heart rate

how many leads does a multichannel recorder monitor at one time

12

the process of studying a current ECG tracing along with older ECGs taken at intervals to note differences in a patient’s condition

serial ECG comparison

which of the following has enhanced a patient’s right to control his or her own health information, making it necessary to handle ECG tracings confidentially

a. CDC

b. AHA

c. HIPAA
d. OSHA

c. HIPAA

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

gain control

which of the following conditions can an ECG machine detect if you set up heart rate limits on the machine

a. myocardial infarction

b. congestive heart failure

c. tachycardia

d. ischemia

c. tachycardia

which type of electrode is most commonly used to perform an ECG

disposable

when serial ECGs are performed on a patient, which of the following guidelines should be followed to ensure accurate results

a. the patient should not move between ECG’s

b. the electrodes must be changed for each successive ECG

c. the electrode placement must be the same for each ECG

d. the patient should not eat or drink between ECGs

c. the electrode placement must be the same for each ECG

you are preparing to perform an ECG on a patient. when you open a new package of disposable electrodes, you notice that the gel appears to have dried out on some of the electrodes. what should you do

discard the electrodes and open another package

ECG machines are calibrated so that

1 cm = 1 mV

how long must the ECG tracing be maintained as part of a patient’s medical record

7 years

unwanted marks on an ECG tracing that are not related to the heart’s electrical activity are known as

artifact

the ECG waveform is indicative of

how the heart is functioning electrically

10 lead wires

6 chest leads, 4 limb leads,

types of leads

3 standard leads, 3 augmented leads, 6 chest leads

standard limb leads are also known as

bipolar leads

what leads form the einthoven triangle

lead I, II, III

augmented leads are also known as

unipolar leads

V1

right sternal border; 4th ICS

V2

left sternal border; 4th ICS

V3

midway between V2 and V4

V4

midclavicular line, 5th ICS

V5

in line with V4 at anterior axillary line

V6

in line with V4 and V5 at mid-axillary line

isoelectric

flat, no current flowing

positive

upright, current flows to positive electrode

negative

downward, current flows away from positive electrode

disposable electrode

normally used for only one ECG with one exception being that when a second ECG is performed on the same patient immediately after the first and the electrodes have not been disturbed

silver electrodes

for hospitalized patients who require frequent ECGs

graph paper may be ____ and easily erased

heat/pressure sensitive

one large (5mm x 5mm) box represents ___ seconds and ___ mV

0.2; 0.5

one small (1mm x 1mm) box represents ___ seconds and ___ mV

0.04; 0.1

which method of calculating heart rate is least accurate

300 method

which method of calculating heart rate is most accurate

1500 method

when would the 6-second method be used

for measuring arrhythmias