Deck 42: Principles of Electrocardiography

Question 1

If the ECG recording appears as a series of irregular, jagged peaks, the medical assistant should

A) check for nearby electric appliances.
B) make sure all electrodes are in contact with the skin.
C) help the patient relax and stay warm.
D) check the cable connections to the electrodes.

Answer 1

help the patient relax and stay warm.

Question 2

________ is the relaxation phase of the heart.

A) Systole
B) Diastole
C) Cardioversion
D) None of the above

Answer 2

Diastole

Question 3

Which statement is true about lead II?

A) It is recorded as the rhythm strip on a cardiac monitor.
B) It records tracings between the left arm and left leg.
C) It records tracings between the left and right arms.
D) It records the electrical activity of the posterior right ventricle.

Answer 3

It is recorded as the rhythm strip on a cardiac monitor.

Question 4

If the ECG recording appears with the baseline rising and falling, the medical assistant should

A) check for nearby electric appliances.
B) check electrode attachment.
C) continue recording the ECG.
D) check the cable connections to the electrodes.

Question 5

To check the standardization of the ECG machine, the medical assistant depresses the standardization button. The stylus should deflect how many millimeters?

A) 20
B) 5
C) 15
D) 10

Question 6

The __________ leads use two limbs to record the heart's electrical activity.

A) augmented
B) standard
C) precordial
D) chest

Question 7

The _________ reflects the time between the end of ventricular contraction and the beginning of ventricular recovery.

A) U wave
B) QRS complex
C) ST segment
D) QT interval

Question 8

On an ECG recording, five 5-mm boxes are seen between the R waves. What is the patient's heart rate per minute?

A) 60
B) 65
C) 70
D) 80

Question 9

Preparation of a patient for an ECG includes

A) placing the electrodes over bony prominences on the arms and legs.
B) making sure the bed is pushed against the wall to stabilize the unit.
C) placing the ground electrode at V6.
D) instructing female patients to remove their bra and pantyhose.

Question 10

Which statement is true about NSR?

A) It is a regular heart rate that falls within the average range of 60 to 80 bpm.
B) It is a heart rate less than 60 bpm.
C) It is a heart rate of greater than 100 bpm.
D) It is an irregular heart rate that falls within the average range of 60 to 80 bpm.

Question 11

The __________ control(s) the rate of heart contraction by initiating contractions 60 to 100 times a minute.

A) AV node
B) SA node
C) bundle of His
D) Purkinje fibers

Question 12

Bradycardia is defined as

A) a faster than normal heart rate.
B) a slower than normal heart rate.
C) chest pain.
D) an irregular heartbeat.

Question 13

Which deflection from the baseline represents the repolarization of the ventricles?

A) P wave
B) T wave
C) ST segment
D) QRS complex

Question 14

What part of the ECG complex represents atrial depolarization?

A) P wave
B) T wave
C) ST segment
D) QRS complex

Question 15

Tachycardia is defined as

A) a faster than normal heart rate.
B) a condition in which the patient has difficulty breathing when lying down.
C) dizzy spells.
D) a condition in which the heartbeat is irregular.

Question 16

Which statement is true about ECG paper?

A) It is not affected by environmental factors, so it is easily maintained in the medical record.
B) It has horizontal and vertical lines at 1-mm intervals.
C) Every fifth line measures 6 mm on each side.
D) None of the above is true.

Question 17

A monitor that a patient wears for 24 hours is called a(n)

A) 12-lead.
B) Holter.
C) Halter.
D) echocardiogram.

Question 18

If the ECG recording appears as a series of small, uniform spikes in the baseline, the medical assistant should

A) check for nearby electric appliances.
B) ask the patient to lie still.
C) help the patient relax and stay warm.
D) check the cable connection to the electrodes.

Question 19

Systole is defined as

A) the contraction of the chambers of the heart.
B) the relaxation of the chambers of the heart.
C) a pounding or racing heart.
D) None of the above

Question 20

In a standard 12-lead ECG, the measurement of current that the heart muscle produces between the right arm electrode and the left arm electrode is known as the

A) standard limb lead I.
B) standard limb lead II.
C) standard limb lead III.
D) augmented lead aVL.

Question 21

Which of the following represents the time from the beginning of atrial contraction to the beginning of ventricular contraction?

A) QRS complex
B) PR interval
C) P wave
D) Q wave

Question 22

Which of the following leads records tracings between the left arm and left leg, which reflects the electrical activity of the inferior surface of the left ventricle?

A) Lead I
B) Lead II
C) Lead III
D) Lead IV

Question 23

Which of the following artifacts appears as a series of uniform small spikes on the ECG paper?

A) Somatic tremor
B) Alternating current interference
C) Interrupted baseline
D) Wandering baseline

Question 24

Which of the following is not an immediate treatment for a heart attack?

A) Administration of nasal oxygen
B) Sublingual nitroglycerin
C) Non-aspirin analgesic
D) Early administration of thrombolytic agents

Question 25

The P wave occurs during the contraction of the __________ and shows the beginning cardiac depolarization.

Question 26

Which of the following may be seen on an ECG when the pathway of the electrical charge is normal, but the rate or rhythm of the heartbeat is altered?

A) Biochemical arrhythmia
B) Atrial arrhythmia
C) Ventricular arrhythmia
D) Sinus arrhythmia
E) Atrial flutter

Question 27

The image created on the ECG paper is made by the

A) heated stylus.
B) ink cartridge.
C) lead wires.
D) felt-tipped pen in the machine.

Question 28

Which cardiac diagnostic tool requires the patient to exercise during the procedure?

A) Stress test
B) Heart scan
C) Holter monitor
D) Event monitor

Question 29

A diary of daily activities is part of the procedure for performing which of the following?

A) Heart scan
B) Stress test
C) Holter monitor
D) Pacemaker reading

Question 30

Which of the following devices monitors the heart rhythm and delivers a shock to the heart if it detects a dangerous ventricular tachycardia or fibrillation?

A) ICD
B) Pacemaker
C) Holter monitor
D) All of the above

Question 31

Which of the following is referred to as sinus bradycardia?

A) A heart rate within the range of 60 to 80 beats per minute
B) A heart rate below 60 beats per minute
C) A heart rate above 100 beats per minute
D) An irregular cardiac rhythm

Question 32

Which of the following leads is placed in the fifth intercostal space, at the left midclavicular line?

A) V₁
B) V₂
C) V₃
D) V₄
E) V₅

Question 33

Atrial flutter may occur if

A) the electrical charge does not pass out of the SA node.
B) the ventricles contract repeatedly.
C) ectopic atrial beats occur.
D) the patient consumes too much caffeine.

Question 34

During the diastole cardiac cycle, which of the following occur?

A) Atria contract and empty of blood
B) Ventricles contract and empty of blood
C) The chambers refill with blood
D) Both A and B
E) All of the above

Question 35

Which statement is not true about V-fib?

A) It typically is preceded by V-tach.
B) It results in death quickly if not treated effectively.
C) The patient can be stabilized with powerful cardiovascular medications.
D) It may lead to asystole.

Question 36

Transverse plane leads on a standard ECG include which of the following?

A) Lead I
B) Lead II
C) Lead III
D) Leads V1 to V6
E) VR, VL, and VF

Question 37

Which of the following is the most critical, life-threatening arrhythmia that can quickly result in death if not treated?

A) Atrial arrhythmia
B) Ventricular tachycardia
C) Ventricular fibrillation
D) Sinus arrhythmia
E) Biochemical arrhythmia

Question 38

Which of the following is seen on the ECG strip of a patient with an MI?

A) Elevated ST segments
B) Elevated T waves
C) Extended QRST segments
D) Absent T wave

Question 39

If a patient has dyspnea or orthopnea, which of the following positions is acceptable for performing an electrocardiogram?

A) Semi-supine position
B) Semi-Fowler's position
C) Prone position
D) Dorsal recumbent position
E) None of the above

Question 40

Electron beam tomography helps screen for cardiac risk by

A) determining the extent of MI damage.
B) assessing the amount of calcium in the coronary arteries.
C) measuring the potassium levels in the heart muscle.
D) determining the strength of the myocardial wall.

Question 41

The __________ is the electric recording of the heart at rest.

Question 42

The first three leads recorded are called the standard, or __________, limb leads, because they each use two limb electrodes to record the heart's electrical activity.

Question 43

The most distal portions of the electrical system of the myocardium are the __________.

Question 44

The T wave indicates ventricular recovery, or __________, of the ventricles.

Question 45

__________ refers to a regular heart rate that ranges from 60 to 90 bpm.

Question 46

A pounding or racing heart, which may or may not indicate a serious heart disorder, is called ____________.

Question 47

An implanted ICD monitors the heart rhythm and automatically performs __________ if it detects a dangerous tachycardia or fibrillation.

Question 48

The QRS complex shows the contraction of both __________ and also reflects the completion of cardiac depolarization.

Question 49

The __________ on an ECG machine creates the image on the ECG paper.

Question 50

Every fifth line on ECG paper, both vertically and horizontally, is darker than the other lines and creates a large square measuring __________ on each side.

Question 51

The electrical activity of the heart is initiated in specialized tissue called the __________, which is located in the superior-posterior wall of the right atrium.

Question 52

The __________ is a combination of all of the electric events that occur in the heart during a single heartbeat.

Question 53

A cardiac __________ is a diagnostic procedure performed to evaluate the patient's myocardial response to measured exercise.

Question 54

Lead __________ records the electrical activity between the left arm and the left leg.

Question 55

A(n) __________ is an ectopic ventricular beat that occurs without a preceding P wave.

Question 56

In the case of __________, the patient has general malaise and muscle cramps. The condition may occur if diuretics are used without potassium supplementation.

Question 57

Describe the placement of each precordial lead.

Question 58

The AV node sends the electric impulse through the __________, which stimulates the right and left ventricular walls.

Question 59

ECG paper has horizontal and vertical lines at __________ intervals.

Question 60

The precordial, or chest, leads are __________ and are designated V₁, V₂, V₃, V₄, V₅, and V₆.

Question 61

A primary responsibility of the medical assistant when obtaining an ECG is to prevent artifacts or correct the problem that created an artifact and try again to print a clean strip. Explain the four artifacts that can occur, give an example of why the artifact might occur, and explain what the medical assistant can do to solve the problem.

Question 62

Patients should not hold their breath during the brief seconds necessary to record an ECG.

Question 63

Lead I records the electrical activity between the right arm and the left arm.

Question 64

Digitalis toxicity may cause specific ECG changes.

Question 65

The electrocardiograph records both the intensity of and the actual time required for each part of the cardiac cycle.

Question 66

Six-channel ECG strips must be cut and mounted before they are placed in the patient's medical record.

Question 67

Polarization is the same thing as myocardial contraction.

Question 68

The patient must be placed in the supine position for an ECG, even if the person has the symptoms of dyspnea and orthopnea.

Question 69

The P wave shows the beginning of cardiac depolarization.

Question 70

Summarize the immediate treatment of an MI. Explain why certain medications are administered.

Question 71

What information should be documented on the ECG strip?

Question 72

The electrodes of the ECG carry cardiac electrical impulses into the machine, where they are magnified by an amplifier.

Question 73

Documentation for an ECG should include whether the patient smoked a cigarette within 15 minutes of the procedure.

Question 74

The SA node is located in the lower wall of the right atrium near the ventricular septum.

Question 75

One of the most specific ECG changes that occurs in patients with an MI is elevated T waves.

Question 76

The SA node stimulates both atria to depolarize at the same time.

Question 77

After electrical stimulation the ventricles contract, emptying oxygen-rich blood into the pulmonary artery.

Question 78

The augmented leads, which include aVR and aVL, record the electrical activity between specific points on the chest wall and within the heart.

Question 79

The skin is an excellent conductor of electrical activity.

Question 80

The standard speed for an ECG recording is 50 mm/sec.