Chapter 8 - Dysrhythmia Management

Question 1

A patient has been diagnosed with premature ventricular contractions. The nurse realizes that this dysrhythmia can result from a weaker than normal stimulus during which action potential period?

1. Absolute refractory period
2. Relative refractory period
3. Supranormal period
4. Subnormal period

Answer 1

Correct Answer: 3

Rationale 1: During the absolute refractory period the cell cannot deal with any new electrical impulses and is completely “resistant” to stimuli.

Rationale 2: In the relative refractory period a stronger than normal electrical stimuli is needed to trigger depolarization. This stimulus could result in premature ventricular contraction.

Rationale 3: During the supranormal period a weaker than normal stimulus can produce depolarization and can result in premature ventricular contractions.

Rationale 4: “Subnormal” is not used to describe a phase or period of the action potential.

Question 2

A patient’s electrocardiogram ST segment tracing is deflected from baseline. The nurse would conduct assessment for which condition?

1. Ventricular muscle injury
2. Atrial muscle injury
3. Respiratory acidosis
4. Hypocalcemia

Answer 2

Correct Answer: 1

Rationale 1: The ST segment represents the completion of ventricular depolarization and the beginning of ventricular repolarization. The segment should be isoelectric, or consistent with the baseline. There should be no deflections present because positive and negative charges are balanced. Deflections in the ST segment usually indicate ventricular muscle injury.

Rationale 2: The ST segment is not associated with atrial depolarization or repolarization.

Rationale 3: The ST segment is not associated with respiratory acidosis.

Rationale 4: Deflection of the ST segment is not associated with calcium levels.

Question 3

A patient’s heart rate averages 86 beats per minute. If this patient is to have continuous electrocardiogram monitoring the nurse will set the rate alarms at which level?

1. Low 76, high 96
2. Low 66, high 106
3. Low 60, high 100
4. Low 80, high 100

Answer 3

Correct Answer: 2

Rationale 1: Setting the alarms at these levels does not reflect the usual protocol.

Rationale 2: Alarms on the monitor are set typically at 20 bpm higher and lower than the patient’s baseline rates. The alarms are left on and audible to the nurse. If the patient’s normal heart rate is 86 beats per minute, the alarms should be set to low 66 and high 106.

Rationale 3: Setting the alarms at these levels does not reflect the usual protocol.

Rationale 4: Setting the alarms at these levels does not reflect the usual protocol.

Question 4

The nurse has determined that the patient has a bundle branch block. In order for this determination which condition must exist?

1. The PR interval must be longer than 0.20 seconds.
2. The ST segment must be elevated.
3. QRS segment should not be longer than 0.128 seconds.
4. The PR interval lengthens with each beat.

Answer 4

Correct Answer: 3

Rationale 1: The length of the PR interval is not associated with bundle branch block.

Rationale 2: Presence of a bundle branch block is not determined by the position of the ST segment.

Rationale 3: The QRS complex should be 0.12 seconds or less in length unless there is a delay in the impulse reaching the ventricles. A widened QRS complex means delayed conduction through the bundle branches or a bundle branch block, abnormal conduction within the ventricles, or early activation of the ventricles through a bypass route.

Rationale 4: Lengthening PR interval is related to heart block, not bundle branch block.

Question 5

The nurse interpreting a patient’s electrocardiogram has just examined the P waves. What is the nurse’s next step?

1. Determine if each P wave is followed by a QRS complex.
2. Measure the PR interval.
3. Diagnose the rhythm.
4. Examine and measure the QRS complex.

Answer 5

Correct Answer: 2

Rationale 1: It is important to determine if each P wave is followed by a QRS complex, but this is not the next step of rhythm interpretation.

Rationale 2: The next structure of importance in the rhythm is the PR interval. The nurse should measure its length.

Rationale 3: In order to make an accurate diagnosis of rhythm, the nurse should follow the standard interpretation sequence.

Rationale 4: The nurse does not examine the QRS complex until the P wave and PR interval have been addressed.

Question 6

A patient is diagnosed with hypermagnesemia. The nurse would assess for which changes on the patient’s cardiac rhythm strip? Select all that apply.

1. Prolonged QT interval
2. Flattened T waves
3. Tall peaked T waves
4. Short QT interval
5. Prolonged PR interval

Answer 6

Correct Answer: 3,5

Rationale 1: Hypercalcemia, not hypermagnesemia, can produce a shortened QT interval. Hypocalcemia can produce a prolonged QT interval.

Rationale 2: Decreased levels of magnesium increase the irritability of the nervous system and can produce a flattened T wave.

Rationale 3: Increased levels of magnesium can produce tall, peaked T waves.

Rationale 4: Hypercalcemia, not hypermagnesemia, can produce a shortened QT interval.

Rationale 5: Hypermagnesemia can result in lengthening of the PR interval.

Question 7

A patient’s admission vital signs were blood pressure 128/64 mm Hg; HR 86 bpm, respirations 16, and temperature 98.6°F. The patient has spiked a temperature of 101.6°F. Which change in heart rate would the nurse anticipate?

1. Increase to 116 bpm
2. Increase to 100 bpm
3. Decrease to 76 bpm
4. Increase or decrease of no more than 5 bpm

Answer 7

Correct Answer: 1

Rationale 1: Hyperthermia increases electrical activity of the heart. Heart rate increases about 10 bpm for each degree Fahrenheit. This patient’s temperature has elevated by 3 degrees F, so a 30 bpm increase to 116 would be expected.

Rationale 2: The nurse would expect a different heart rate change.

Rationale 3: Temperature elevation causes an elevation of heart rate.

Rationale 4: The nurse would anticipate a greater change than 5 bpm.

Question 8

A patient presents to the emergency department and says, “I am so dizzy that it is scaring me.” Monitoring reveals the patient’s blood pressure is 78/52 mm Hg and heart rate is 50 beats per minutes. Which nursing intervention is indicated?

1. Administer anti-anxiety medication.
2. Administer atropine.
3. Instruct the patient to cough forcefully.
4. Monitor the patient while contacting the primary care provider.

Answer 8

Rationale 1: The patient’s anxiety is likely due to fear of the unknown. Anti-anxiety medication is not indicated.

Rationale 2: Sinus bradycardia is not treated unless the person experiences symptoms of decreased cardiac output, such as syncope, hypotension, and angina. Symptomatic sinus bradycardia is treated by administering atropine because it blocks the parasympathetic innervation to the SA node, allowing normal sympathetic innervation to gain control and increase SA node firing. The patient is symptomatic so atropine is indicated.

Rationale 3: Forceful coughing will not reverse this patient’s symptoms.

Rationale 4: The patient requires intervention.

Question 9

A patient in the emergency department has a heart rate of 140 bpm. Which nursing interventions are indicated? Select all that apply.

1. Assess the patient’s temperature.
2. Administer atropine.
3. Present a calm demeanor.
4. Assess the patient for pain.
5. Prepare for intubation.

Answer 9

Correct Answer: 1,3,4

Rationale 1: Increased temperature can result in tachycardia.

Rationale 2: Atropine is not indicated for tachycardia.

Rationale 3: Anxiety can result in tachycardia. The nurse should present a calm and confident demeanor.

Rationale 4: Pain can result in tachycardia. If pain is present it should be treated promptly.

Rationale 5: Unless there are other assessment findings indicating the need for intubation this intervention is not necessary.

Question 10

A patient’s cardiac monitor reveals a regular rhythm with a rate of 240 bpm. No P waves are distinguishable. The patient is alert and says, “My heart is racing.” What nursing intervention is indicated?

1. Gather equipment to begin anticoagulant therapy.
2. Defibrillate the patient.
3. Prepare the patient for immediate cardioversion.
4. Ask the patient to bear down as if moving the bowels.

Answer 10

Rationale 1: This rhythm is supraventricular tachycardia. At this point anticoagulant therapy is not indicated.

Rationale 2: The patient is alert and responsive. Defibrillation is not indicated.

Rationale 3: If the patient was in extreme distress elective cardioversion would be indicated. Since this patient is alert, cardioversion is not indicated.

Rationale 4: This patient has supraventricular tachycardia. This rhythm can be treated with Valsalva’s maneuver, which is elicited by having the patient bear down as if moving the bowels.

Question 11

A patient’s atrial fibrillation has been refractory to treatment. The nurse would prioritize which discharge instructions?

1. Avoiding stressful situations
2. Anticoagulant therapy precautions
3. The importance of daily weights
4. How to check blood pressure at home

Answer 11

Correct Answer: 2

Rationale 1: There is no specific reason the patient should avoid stressful situations any more than any other patient with a cardiac disorder.

Rationale 2: Patients in atrial fibrillation require anticoagulation such as warfarin therapy. The nurse must provide instructions regarding precautions that are made necessary by this therapy.

Rationale 3: This patient has potential for developing congestive heart failure, so daily weights may be necessary. However, this is not the instruction with the highest priority.

Rationale 4: The patient who is in atrial fibrillation may be instructed to monitor blood pressure, but this is not the priority discharge teaching.

Question 12

A patient has a normal QRS complex on an electrocardiogram which is followed by the P wave. Heart rate is 80 bpm and regular and the patient has no complaints. What nursing action is indicated?

1. Document presence of atrial escape rhythm.
2. Review the patient’s medication history.
3. STAT page the patient’s health care provider.
4. Notify the nurse manager that it may become necessary to call the rapid response team.

Answer 12

Correct Answer: 2

Rationale 1: When the normal QRS is followed by a P wave the rhythm is junctional.

Rationale 2: Junctional rhythm may be caused by several medications. The nurse should review the medication list for possible causative drugs.

Rationale 3: The health care provider should be altered to the presence of junctional rhythm, but there is no cause for a STAT page.

Rationale 4: This assessment indicates presence of junctional rhythm. The patient is asymptomatic with an adequate ventricular rate, so it is not likely that the nurse will need to call the rapid response team.

Question 13

A patient’s cardiac rhythm strip reveals rate of 78, PR interval of 0.08 seconds, a normally configured QRS, and an upright T wave. Which medication does the nurse recognize as most often associated with development of this rhythm?

1. Potassium supplement
2. Warfarin
3. Digoxin
4. Tocainide

Answer 13

Correct Answer: 3

Rationale 1: High potassium levels may be implicated in slow junctional escape rhythms, but this rate is normal.

Rationale 2: Warfarin does not cause junctional rhythm.

Rationale 3: Digitalis decreases the automaticity of the AV node and slows conduction between the SA and AV node so therefore, digitalis toxicity can precipitate junctional rhythms. The dysrhythmia is treated by withholding the medication.

Rationale 4: Tocanide is a class 1B drug that has few ECG effects.

Question 14

A patient is having multifocal premature ventricular contractions (PVCs). What nursing interventions are indicated? Select all that apply.

1. Administer oxygen.
2. Withhold the next digoxin dose.
3. Administer atropine.
4. Monitor the patient closely for other dysrhythmias.
5. Consult with the health care provider.

Answer 14

Correct Answer: 1,4,5

Rationale 1: Hypoxemia can cause PVCs. The nurse should implement emergency orders for oxygen therapy.

Rationale 2: Multifocal PVCs are not associated with use of digoxin.

Rationale 3: Atropine is used to increase heart rate. It is not indicated for use in patients with ventricular irritability.

Rationale 4: Multifocal PVCs may herald additional dysrhythmias such as ventricular tachycardia or ventricular fibrillation.

Rationale 5: Presence of multifocal PVCs indicates increased ventricular irritability. The nurse should contact the health care provider and discuss treatment options, such as adding medications.

Question 15

The nurse notes this rhythm on the patient’s cardiac monitor. What is the nurse’s priority intervention?

1. Check the patient’s pulse.
2. Administer oxygen.
3. Call a code blue.
4. Prepare to cardiovert the patient.

Answer 15

Correct Answer: 1

Rationale 1: The nurse should first check the patient’s pulse before taking other actions. This tracing could represent ventricular fibrillation or a loose or damaged monitor lead. The nurse must assess the patient and not depend solely on the cardiac monitor.

Rationale 2: Oxygen administration may be indicated, but this is not the nurse’s highest priority.

Rationale 3: The nurse may need to call a code blue but this is not a certainty. Another intervention takes priority.

Rationale 4: The nurse should not assume that this patient requires cardioversion.

Question 16

A patient develops ventricular tachycardia on the cardiac monitor. The patient says “My heart is racing” as the nurse determines a rapid pulse is present. What is the nurse’s priority intervention?

1. Call respiratory therapy to prepare a mechanical ventilator.
2. Draw blood for arterial blood gases.
3. Prepare to for a change in intravenous fluid being administered.
4. Monitor the patient for loss of consciousness.

Answer 16

Correct Answer: 4

Rationale 1: This patient may arrest and need mechanical ventilation, but this is not the nurse’s first priority.

Rationale 2: The patient may need multiple lab tests, but this is not the nurse’s priority intervention.

Rationale 3: This patient may need a different IV fluid, but this is not the priority intervention.

Rationale 4: Patients can be alert while experiencing ventricular tachycardia; however, as cardiac output falls, a loss of consciousness may occur. When this occurs cardioversion may be necessary. The nurse’s priority is to assess the patient.

Question 17

A patient, experiencing ventricular fibrillation, was resuscitated with lidocaine, then magnesium, and lastly amiodarone. Which medication will the nurse most likely provide as a continuous infusion for this patient?

1. Lidocaine
2. Magnesium
3. Atropine
4. Amiodarone

Answer 17

Correct Answer: 4

Rationale 1: Lidocaine was not successful in converting the patient’s rhythm and would probably not prevent the return of ventricular fibrillation.

Rationale 2: Magnesium did not successfully stop the patient’s ventricular fibrillation and is not likely to be administered in an attempt to control the rhythm.

Rationale 3: The patient did not receive atropine during the resuscitation. It is not indicated now.

Rationale 4: Once the patient has converted from ventricular fibrillation and has a pulse, a continuous infusion of the last drug used to convert the rhythm is initiated. Since the patient last received amiodarone, the nurse will most likely provide a continuous infusion of the medication for the patient.

Question 18

A patient’s cardiac monitor reveals heart rate of 40 bpm with an irregular rate. The PR intervals are constant and there are P waves with no QRS to follow. The QRS complexes are wider than normal. The patient complains of severe dizziness and nausea. Which nursing interventions are indicated? Select all that apply.

1. Administer atropine.
2. Prepare to cardiovert the patient.
3. Prepare for placement of a temporary pacemaker.
4. Administer epinephrine.
5. Ask the patient to cough forcefully.

Answer 18

Correct Answer: 1,3,4

Rationale 1: This rhythm represents Mobitz type II second-degree AV block and the patient is symptomatic. Atropine is indicated.

Rationale 2: Cardioversion is not used to treat this type of dysrhythmia.

Rationale 3: This rhythm is a Mobitz type II second-degree block and the patient is symptomatic. Type II second-degree blocks are generally treated by inserting a pacemaker.

Rationale 4: Dopamine or epinephrine is used in severe symptomatic bradycardia like the patient is experiencing.

Rationale 5: Forceful coughing will not improve this patient’s cardiac status.

Question 19

A patient has a new onset of a left bundle branch block (LBBB) seen on a 12 lead ECG. What is the nurse’s primary intervention?

1. Increase oxygen.
2. Elevate the head of the bed to a 30-degree angle.
3. Ask the patient if he is having chest pain.
4. Reposition the chest leads and assess for any changes.

Answer 19

Correct Answer: 3

Rationale 1: The patient may or may not need an increase in oxygen, so this is not the primary nursing intervention.

Rationale 2: Elevation of the head of the patient’s bed will not correct a bundle branch block.

Rationale 3: New onset left bundle branch block may indicate a myocardial infarction is occurring. The priority intervention is to assess for chest pain or other findings associated with MI.

Rationale 4: There is no indication that repositioning of the chest leads is indicated or that it will change the presence of a LBBB.

Question 20

A patient with a temporary pacemaker has this cardiac rhythm. What nursing intervention is indicated?

1. Turn the impulse generator off, wait 30 seconds, and turn it back on.
2. Call for a STAT portable chest x-ray.
3. Check for a damaged lead wire.
4. Decrease the pacemaker sensitivity.

Answer 20

Correct Answer: 3

Rationale 1: The nurse should not term the impulse generator off for this rhythm.

Rationale 2: The reason for this rhythm strip is not likely to be diagnosed by chest x-ray.

Rationale 3: This rhythm strip represents failure to capture, which can be caused by low battery level, leads that are not firmly attached to the pacemaker, or damaged lead wires.

Rationale 4: This rhythm strip represents failure to capture. Decreasing pacemaker sensitivity will not affect capture.