Deck 49: Principles of Electrocardiography

Question 1

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

Answer 1

False

Question 2

Digitalis toxicity may cause specific ECG changes.

Answer 2

True

Question 3

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

Answer 3

True

Question 4

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

Question 5

The right leg is used to ground the recording of the augmented leads.

Question 6

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

Question 7

The P wave is a reflection of atrial repolarization.

Question 8

An abrasive device must be applied to each electrode placement site before an ECG can be obtained.

Question 9

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

Question 10

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

Question 11

The skin is an excellent conductor of electrical activity.

Question 12

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

Question 13

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

Question 14

The QRS complex shows as a negative deflection in V₁ and V₂ views.

Question 15

Patients should hold their breath during the brief seconds necessary to record an ECG.

Question 16

Polarization is the same thing as myocardial contraction.

Question 17

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

Question 18

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

Question 19

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

Question 20

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

Question 21

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 22

A patient in V-tach does not have a pulse.

Question 23

Sinus arrhythmia is a result of the abnormal flow of the electrical system of the heart.

Question 24

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 25

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 26

If the ECG recording appears as a series of interruptions on 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 connections to the electrodes

Question 27

PACs may be recorded in patients who smoke or consume large quantities of caffeine.

Question 28

In which direction should arm electrodes be pointed when attached to the patient in preparation for the ECG?

A)Toward the head
B)Toward the feet
C)Away from the midline of the body
D)Toward the center of the body

Question 29

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 30

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

A)12-lead
B)Holter
C)halter
D)echocardiogram

Question 31

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

Question 32

A cardiac event monitor must be worn at all times, even during bathing, to detect cardiac abnormalities.

Question 33

Patients with a history of V-fib may be treated with an ICD.

Question 34

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

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

Question 35

PVCs are recorded when the ventricles depolarize before a P wave.

Question 36

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 37

The medical assistant may assist with pacemaker implantation in the physician's office setting.

Question 38

What part of the ECG complex represents atrial depolarization?

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

Question 39

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 40

The greatest deflection from the baseline on the ECG is the:

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

Question 41

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 42

The __________ controls 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 43

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 44

A patient with Parkinson's disease may have which of the following artifacts?

A)AC
B)Somatic tremor
C)Wandering baseline
D)Interrupted baseline

Question 45

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 46

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 47

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

Question 48

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 49

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 50

________ is the relaxation phase of the heart.

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

Question 51

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 52

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 53

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

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

Question 54

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 55

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 56

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

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

Question 57

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.

Question 58

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

Question 59

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 60

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

Question 61

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

Question 62

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

Question 63

__________ records the electrical activity from midway between the left leg and the left arm to the right arm.

Question 64

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

Question 65

ECG paper has horizontal and vertical lines at __________ intervals.

Question 66

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

Question 67

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 68

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

Question 69

When a patient is in __________, the person has no pulse.

Question 70

Describe the placement of each precordial lead.

Question 71

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 72

What information should be documented on the ECG strip?

Question 73

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

Question 74

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 75

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

Question 76

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

Question 77

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

Question 78

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

Question 79

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

Question 80

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