Chapter 36 Dysrhythmias Flashcards
To determine whether there is a delay in impulse conduction through the atria, the nurse will measure the duration of the patient’s
a. P wave.
b. Q wave.
c. P-R interval.
d. QRS complex.
ANS: A
The P wave represents the depolarization of the atria. The P-R interval represents depolarization of the atria, atrioventricular (AV) node, bundle of His, bundle branches, and the Purkinje fibers. The QRS represents ventricular depolarization. The Q wave is the first negative deflection following the P wave and should be narrow and short.
The nurse needs to quickly estimate the heart rate for a patient with a regular heart rhythm. Which method will be best to use?
a. Count the number of large squares in the R-R interval and divide by 300.
b. Print a 1-minute electrocardiogram (ECG) strip and count the number of QRS complexes.
c. Calculate the number of small squares between one QRS complex and the next and divide into 1500.
d. Use the 3-second markers to count the number of QRS complexes in 6 seconds and multiply by 10.
ANS: D
This is the quickest way to determine the ventricular rate for a patient with a regular rhythm. All the other methods are accurate, but take longer.
A patient has a junctional escape rhythm on the monitor. The nurse will expect the patient to have a heart rate of _____ beats/minute.
a. 15 to 20
b. 20 to 40
c. 40 to 60
d. 60 to 100
ANS: C
If the sinoatrial (SA) node fails to discharge, the atrioventricular (AV) node will automatically discharge at the normal rate of 40 to 60 beats/minute. The slower rates are typical of the bundle of His and the Purkinje system and may be seen with failure of both the SA and AV node to discharge. The normal SA node rate is 60 to 100 beats/minute.
The nurse obtains a rhythm strip on a patient who has had a myocardial infarction and makes the following analysis: no visible P waves, P-R interval not measurable, ventricular rate 162, R-R interval regular, and QRS complex wide and distorted, QRS duration 0.18 second. The nurse interprets the patient’s cardiac rhythm as
a. atrial flutter.
b. sinus tachycardia.
c. ventricular fibrillation.
d. ventricular tachycardia.
ANS: D
The absence of P waves, wide QRS, rate >150 beats/minute, and the regularity of the rhythm indicate ventricular tachycardia. Atrial flutter is usually regular, has a narrow QRS configuration, and has flutter waves present representing atrial activity. Sinus tachycardia has P waves. Ventricular fibrillation is irregular and does not have a consistent QRS duration.
The nurse notes that a patient’s cardiac monitor shows that every other beat is earlier than expected, has no visible P wave, and has a QRS complex that is wide and bizarre in shape. How will the nurse document the rhythm?
a. Ventricular couplets
b. Ventricular bigeminy
c. Ventricular R-on-T phenomenon
d. Multifocal premature ventricular contractions
ANS: B
Ventricular bigeminy describes a rhythm in which every other QRS complex is wide and bizarre looking. Pairs of wide QRS complexes are described as ventricular couplets. There is no indication that the premature ventricular contractions (PVCs) are multifocal or that the R-on-T phenomenon is occurring.
A patient has a normal cardiac rhythm and a heart rate of 72 beats/minute. The nurse determines that the P-R interval is 0.24 seconds. The most appropriate intervention by the nurse would be to
a. notify the health care provider immediately.
b. give atropine per agency dysrhythmia protocol.
c. prepare the patient for temporary pacemaker insertion.
d. document the finding and continue to monitor the patient.
ANS: D
First-degree atrioventricular (AV) block is asymptomatic and requires ongoing monitoring because it may progress to more serious forms of heart block. The rate is normal, so there is no indication that atropine is needed. Immediate notification of the health care provider about an asymptomatic rhythm is not necessary.
A patient who was admitted with a myocardial infarction experiences a 45-second episode of ventricular tachycardia, then converts to sinus rhythm with a heart rate of 98 beats/minute. Which of the following actions should the nurse take next?
a. Immediately notify the health care provider.
b. Document the rhythm and continue to monitor the patient.
c. Perform synchronized cardioversion per agency dysrhythmia protocol.
d. Prepare to give IV amiodarone (Cordarone) per agency dysrhythmia protocol.
ANS: D
The burst of sustained ventricular tachycardia indicates that the patient has significant ventricular irritability, and antidysrhythmic medication administration is needed to prevent further episodes. The nurse should notify the health care provider after the medication is started. Defibrillation is not indicated given that the patient is currently in a sinus rhythm. Documentation and continued monitoring are not adequate responses to this situation.
After the nurse gives IV atropine to a patient with symptomatic type 1, second-degree atrioventricular (AV) block, which finding indicates that the medication has been effective?
a. Increase in the patient’s heart rate
b. Increase in strength of peripheral pulses
c. Decrease in premature atrial contractions
d. Decrease in premature ventricular contractions
ANS: A
Atropine will increase the heart rate and conduction through the AV node. Because the medication increases electrical conduction, not cardiac contractility, the quality of the peripheral pulses is not used to evaluate the drug effectiveness. The patient does not have premature atrial or ventricular contractions.
A patient with dilated cardiomyopathy has new onset atrial fibrillation that has been unresponsive to drug therapy for several days. The priority teaching needed for this patient would include information about
a. anticoagulant therapy.
b. permanent pacemakers.
c. electrical cardioversion.
d. IV adenosine (Adenocard).
ANS: A
Atrial fibrillation therapy that has persisted for more than 48 hours requires anticoagulant treatment for 3 weeks before attempting cardioversion. This is done to prevent embolization of clots from the atria. Cardioversion may be done after several weeks of anticoagulation therapy. Adenosine is not used to treat atrial fibrillation. Pacemakers are routinely used for patients with bradydysrhythmias. Information does not indicate that the patient has a slow heart rate.
Which information will the nurse include when teaching a patient who is scheduled for a radiofrequency catheter ablation for treatment of atrial flutter?
a. The procedure will prevent or minimize the risk for sudden cardiac death.
b. The procedure will use cold therapy to stop the formation of the flutter waves.
c. The procedure will use electrical energy to destroy areas of the conduction system.
d. The procedure will stimulate the growth of new conduction pathways between the atria.
ANS: C
Radiofrequency catheter ablation therapy uses electrical energy to “burn” or ablate areas of the conduction system as definitive treatment of atrial flutter (i.e., restore normal sinus rhythm) and tachydysrhythmias. All other statements regarding the procedure are incorrect.
After providing a patient with discharge instructions on the management of a new permanent pacemaker, the nurse knows that teaching has been effective when the patient states
a. “I will avoid cooking with a microwave oven or being near one in use.”
b. “It will be 1 month before I can take a bath or return to my usual activities.”
c. “I will notify the airlines when I make a reservation that I have a pacemaker.”
d. “I won’t lift the arm on the pacemaker side up very high until I see the doctor.”
ANS: D
The patient is instructed to avoid lifting the arm on the pacemaker side above the shoulder to avoid displacing the pacemaker leads. The patient should notify airport security about the presence of a pacemaker before going through the metal detector, but there is no need to notify the airlines when making a reservation. Microwave oven use does not affect the pacemaker. The insertion procedure involves minor surgery that will have a short recovery period.
Which intervention by a new nurse who is caring for a patient who has just had an implantable cardioverter-defibrillator (ICD) inserted indicates a need for more education about care of patients with ICDs?
a. The nurse assists the patient to do active range of motion exercises for all extremities.
b. The nurse assists the patient to fill out the application for obtaining a Medic Alert ID.
c. The nurse gives amiodarone (Cordarone) to the patient without first consulting with the health care provider.
d. The nurse teaches the patient that sexual activity usually can be resumed once the surgical incision is healed.
ANS: A
The patient should avoid moving the arm on the ICD insertion site until healing has occurred in order to prevent displacement of the ICD leads. The other actions by the new nurse are appropriate for this patient.
Which action should the nurse perform when preparing a patient with supraventricular tachycardia for cardioversion who is alert and has a blood pressure of 110/66 mm Hg?
a. Turn the synchronizer switch to the “off” position.
b. Give a sedative before cardioversion is implemented.
c. Set the defibrillator/cardioverter energy to 360 joules.
d. Provide assisted ventilations with a bag-valve-mask device.
ANS: B
When a patient has a nonemergency cardioversion, sedation is used just before the procedure. The synchronizer switch is turned “on” for cardioversion. The initial level of joules for cardioversion is low (e.g., 50). Assisted ventilations are not indicated for this patient.
A 20-year-old has a mandatory electrocardiogram (ECG) before participating on a college soccer team and is found to have sinus bradycardia, rate 52. Blood pressure (BP) is 114/54, and the student denies any health problems. What action by the nurse is most appropriate?
a. Allow the student to participate on the soccer team.
b. Refer the student to a cardiologist for further diagnostic testing.
c. Tell the student to stop playing immediately if any dyspnea occurs.
d. Obtain more detailed information about the student’s family health history.
ANS: A
In an aerobically trained individual, sinus bradycardia is normal. The student’s normal BP and negative health history indicate that there is no need for a cardiology referral or for more detailed information about the family’s health history. Dyspnea during an aerobic activity such as soccer is normal.
When analyzing the rhythm of a patient’s electrocardiogram (ECG), the nurse will need to investigate further upon finding a(n)
a. isoelectric ST segment.
b. P-R interval of 0.18 second.
c. Q-T interval of 0.38 second.
d. QRS interval of 0.14 second.
ANS: D
Because the normal QRS interval is 0.04 to 0.10 seconds, the patient’s QRS interval of 0.14 seconds indicates that the conduction through the ventricular conduction system is prolonged. The P-R interval and Q-T interval are within normal range, and ST segment should be isoelectric (flat).
