Flashcards in LA#5 ( Cardio (2)) Chapters 37, 38, 39, 40 in Med Surg Deck (100)
In analyzing a patient’s electrocardiogram (ECG) rhythm strip, the nurse uses the knowledge that the time of the conduction of an impulse through the Purkinje fibres is represented by which of the following changes?
a. P wave
b. PR interval
c. QT interval
d. QRS complex
The PR interval represents depolarization of the atria, atrioventricular (AV) node, bundle of His, bundle branches, and Purkinje fibres, up to the point of depolarization of the ventricular cells.
Which of the following is an abnormal ECG value for a PR interval duration?
a. 0.6 second
b. 0.12 second
c. 0.24 second
d. 0.30 second
The normal duration of a PR interval is 0.12 to 0.20 seconds.
A patient has a sinus arrest with a junctional escape rhythm. What would the nurse expect the patient’s pulse rate to be?
a. 15 to 20 beats/min
b. 20 to 40 beats/min
c. 40 to 60 beats/min
d. 60 to 100 beats/min
If the sinoatrial node fails to discharge, the junction will automatically discharge at the normal junctional rate of 40 to 60 beats/min.
A patient has a dysrhythmia that requires careful monitoring of atrial activity. Which lead will be best to use for continuous monitoring?
Leads II and MCL1 are the best leads for visualization of P waves, which reflect atrial activity.
The nurse obtains a monitor strip on a patient admitted to the coronary care unit with a myocardial infarction (MI) and makes the following analysis: P wave not apparent; ventricular rate 142 beats/min, R-R interval regular; PR interval not measurable; and QRS complex wide and distorted, greater than 0.14 second. The nurse interprets this patient’s cardiac rhythm as which of the following?
a. Atrial fibrillation
b. Sinus tachycardia
c. Ventricular fibrillation
d. Ventricular tachycardia
The absence of P waves, wide QRS, rate greater than 150 beats/min, and regularity of the rhythm indicate ventricular tachycardia.
The nurse determines that a patient has ventricular bigeminy when the rhythm strip indicates which of the following changes?
a. Conduction is originating in the AV node.
b. Every other QRS complex is wide and starts prematurely.
c. The ventricular rate is between 150 and 250 beats/min.
d. The rhythm of the SA node is coupled with long pauses between every two beats.
Ventricular bigeminy describes a rhythm in which every other QRS complex is wide and bizarre looking.
A patient has a normal cardiac rhythm strip, except that the PR interval is 0.34 seconds. What is the appropriate nursing intervention?
a. Notify the physician.
b. Administer atropine per protocol.
c. Prepare the patient for temporary pacemaker insertion.
d. Document the finding, and continue to monitor the patient.
First-degree AV block is asymptomatic and requires ongoing monitoring because it may progress to more serious forms of heart block.
A patient with diabetes mellitus is admitted unresponsive to the emergency department (ED). Initial laboratory findings are serum potassium 2.8 mmol/L, serum sodium 138 mmol/L, serum chloride 90 mmol/L, and blood glucose 34.9 mmol/L (628 mg/dL). Cardiac monitoring shows multifocal premature ventricular contractions (PVCs). What does the nurse understand that the patient’s PVCs are most likely caused by?
Hypokalemia increases the risk for ventricular dysrhythmias such as PVCs, ventricular tachycardia, and ventricular fibrillation.
The nurse retrieves data from the cardiac monitor that indicates that a patient with an MI experienced a 45-second episode of ventricular tachycardia before a normal sinus rhythm and a heart rate of 98 were re-established. What is the most appropriate initial nursing action?
a. Notify the physician.
b. Administer antidysrhythmic drugs per protocol.
c. Elevate the head of the bed, and administer oxygen at 6 L/min.
d. Continue to monitor the patient’s cardiac rhythm without other interventions at this time.
The burst of sustained ventricular tachycardia indicates that the patient has significant ventricular irritability, and antidysrhythmic medication administration is needed to prevent further episodes.
A patient with myocardial damage develops a type I, second-degree AV block. The nurse administers IV atropine as prescribed. The nurse determines that the medication has been effective on finding which of the following changes?
a. A decrease in ventricular response
b. A decrease in premature contractions
c. An increase in the patient’s heart rate
d. Increased carotid and peripheral pulse volume
Atropine will increase the heart rate and conduction through the AV node
What is the most accurate way to calculate the heart rate from an ECG?
a. Count the number of R-R intervals in 6 seconds, and multiply by 10.
b. Count the number of small squares between the R-R interval, and divide by 1500.
c. Count the number of QRS complexes in 1 minute.
d. Count the large squares between one R-R interval, and divide by 300.
The most accurate way to obtain a heart rate from an ECG is to count the number of QRS complexes in 1 minute.
The cardiac monitor alarm goes off for a patient being monitored in the coronary care unit, and the nurse notes a cardiac pattern of undulations of varying contours and amplitude with no measurable ECG pattern. The patient is unconscious, with no pulse or respirations. After calling for assistance, what should the nurse do?
a. Start basic cardiopulmonary resuscitation (CPR).
b. Administer a bolus dose of epinephrine.
c. Prepare the patient for endotracheal intubation.
d. Wait for the defibrillator to arrive at the bedside.
The patient’s rhythm and assessment indicate ventricular fibrillation and cardiac arrest; therefore, the initial actions include calling for help and initiating CPR until defibrillation is possible.
During the change-of-shift report, the nurse learns that a patient with a large MI has been having frequent PVCs. What will the nurse check when monitoring the patient for the effects of PVCs?
a. The patient’s medications
b. The patient’s oxygen saturation
c. The patient’s apical–radial heart rate
d. The patient’s recent electrolyte values
It is important to assess the patient’s apical–radial pulse rate because PVCs often do not generate a sufficient ventricular contraction to result in a peripheral pulse, which can lead to a pulse deficit.
How would the nurse document a dysrhythmia pattern that has a sawtooth-shape P wave, a variable PR interval, and a normal QRS complex?
a. Junctional rhythms
b. Atrial flutter
c. Sinus bradycardia
d. Atrial fibrillation
A dysrhythmia pattern that has a sawtooth-shape P wave, a variable PR interval, and a normal QRS complex is an atrial flutter.
Which classification of antidysrhythmia drugs has no effect on ECG?
a. Class I: sodium channel blockers
b. Class II: β-adrenergic blockers
c. Class III: potassium channel blockers
d. Class IV: calcium channel blockers
Class I: sodium channel blockers have no effect on ECG.
The nurse is doing discharge teaching with a patient who is going home with an implantable cardioverter–defibrillator (ICD). Which of the following instructions should the nurse give the patient?
a. Keep the incision dry for at least 2 weeks after ICD insertion.
b. The ICD will not set off a metal detector in an airport, so it is all right to travel.
c. You should have a routine ICD check every 2 to 3 months.
d. It is all right to drive as soon as you are discharged.
Routine ICD check with interrogator–programmer device is needed every 2 to 3 months.
A patient has a permanent pacemaker inserted for treatment of chronic atrial fibrillation with slow ventricular response. The nurse recognizes that the pacemaker is used for the patient to do which of the following?
a. Prevent ventricular irritability.
b. Override the ectopic stimulus in the atria.
c. Fire an impulse every second to maintain a heart rate of 60 beats/min.
d. Discharge an electrical stimulus when no ventricular depolarization is sensed.
The permanent pacemaker will discharge when the ventricular rate drops below the set rate.
A patient has received instruction on the management of her permanent pacemaker before discharge from the hospital. The nurse recognizes that teaching has been effective when the patient makes which of the following statements?
a. “I won’t lift the arm on the pacemaker side up very high until I see the doctor.”
b. “I will notify the airlines when I make a reservation that I have a pacemaker.”
c. “I must avoid cooking with a microwave oven or being near a microwave in use.”
d. “It will be 6 weeks before I can take a bath or return to my usual activities.”
The patient is instructed to avoid lifting the arm on the pacemaker side above the shoulder to avoid displacing the pacemaker leads.
A patient who has been successfully resuscitated twice following sudden cardiac death has a transvenous ICD implanted for management of ventricular dysrhythmias. When performing discharge teaching with the patient, what is most important for the nurse to instruct the patient and family about?
a. He will no longer need to take medications to control his dysrhythmias.
b. If the ICD fires and he loses consciousness, 911 should be called.
c. His family will not need to learn CPR because he has the automatic defibrillator available.
d. The ICD device rarely sets off airport security alarms, and travel without restrictions is allowed.
If the ICD fires and the patient continues to have symptoms of cardiac arrest, activation of the emergency response system is indicated.
A patient with supraventricular tachycardia is to receive cardioversion. What should the nurse know about the use of cardioversion?
a. A defibrillator is programmed to deliver a countershock on the T wave.
b. The amount of voltage used is 400 J.
c. The patient should be sedated before the procedure, if possible.
d. The procedure is the same as defibrillation, except that the patient is more hemodynamically stable.
When a patient has a nonemergency cardioversion, sedation is used just before the procedure.
A patient’s sinus rhythm rate is 62 beats/min. The PR interval is 0.18 seconds at 0100 hours, 0.20 seconds at 1230 hours, and 0.23 seconds at 1600 hours. Which action should the nurse take?
a. Document the patient’s rhythm, and continue to monitor.
b. Prepare for possible pacemaker insertion.
c. Hold the ordered metoprolol (Lopressor), and call the physician.
d. Give the as-needed dose of lidocaine (Xylocaine).
The patient has progressive first-degree AV block, and the β-blocker should be held until discussing the medication with the physician.
A patient develops sinus bradycardia at a rate of 32 beats/min, has a BP of 80/36 mm Hg, and is complaining of feeling faint. Which action should the nurse take?
a. Continue to monitor the rhythm and BP.
b. Obtain and apply the transcutaneous pacemaker.
c. Give the scheduled dose of diltiazem (Cardizem).
d. Have the patient perform the Valsalva manoeuvre.
The patient is experiencing symptomatic bradycardia, and treatment with the transcutaneous pacemaker is appropriate.
A 21-year-old college student arrives at the student health centre at the end of the quarter complaining, “My heart is skipping beats.” The nurse obtains an ECG and notes the presence of occasional PVCs. What action should the nurse take first?
a. Ask the patient about any history of coronary artery disease.
b. Question the patient about current stress level and coffee use.
c. Have the patient transported to the hospital ED.
d. Administer O2 to the patient at 2 to 3 L/min using nasal prongs.
In a patient with a normal heart, occasional PVCs are a benign finding. The timing of the PVCs suggests stress or caffeine as a possible etiological factor.
A 19-year-old student has a mandatory ECG before participating on a university swim team and is found to have sinus bradycardia, rate 52 beats/min. BP is 114/54 mm Hg, and the student denies any health problems. Which nursing action is appropriate?
a. Refer the student to a cardiologist for further assessment.
b. Allow the student to participate on the swim team.
c. Obtain more detailed information about the student’s health history.
d. Tell the student to stop swimming immediately if any dyspnea occurs.
In an aerobically trained individual, sinus bradycardia is normal. The student’s normal BP and negative health history indicate that a cardiology referral or more detailed information about the health history is not necessary. Dyspnea during an aerobic activity such as swimming is normal.
When analyzing the waveforms of a patient’s ECG, which finding will the nurse need to investigate further?
a. PR interval of 0.18 second
b. QRS interval of 0.14 second
c. T wave of 0.16 second
d. QT interval of 0.34 second
Because the normal QRS interval is 0.06 to 0.10 second, the patient’s QRS interval of 0.14 second indicates that the conduction through the ventricular conduction system is prolonged.
The nurse obtains a health history from a patient with a prosthetic mitral valve who has symptoms of infective endocarditis (IE). Which is the most appropriate question for the nurse to ask?
a. “Do you have a history of a heart attack?”
b. “Have you had any recent immunizations?”
c. “Have you been to the dentist lately?”
d. “Do you have a family history of endocarditis?”
Dental procedures place the patient with a prosthetic mitral valve at risk for IE.
The physician writes the following admitting orders for a patient with suspected IE who has fever and chills: ceftriaxone (Rocephin) 1.0 g intravenous (IV) piggyback every 12 hours, aspirin for a temperature above 38.9°C, blood cultures × 3, complete blood count, and electrocardiogram (ECG). When admitting the patient, to which of the following orders should the nurse give the highest priority?
a. Scheduling the ECG
b. Initiating the intravenous (IV) antibiotic
c. Obtaining the blood cultures
d. Administering the antipyretic agent
Treatment of the IE with antibiotics should be started as quickly as possible, but it is essential to obtain blood cultures before initiating antibiotic therapy to obtain accurate sensitivity results.
During the assessment of a patient with IE, what would the nurse expect to find?
a. A new regurgitant murmur
b. Splinter hemorrhages of the lips
c. Dyspnea and a dry, hacking cough
d. Substernal chest pain and pressure
New regurgitant murmurs occur in IE because vegetation on the valves prevents valve closure.
A patient is admitted to hospital with a diagnosis of myocarditis. The nurse knows that early cardiac manifestations will appear approximately how long after viral infection?
a. 24 to 48 hours
b. 3 to 5 days
c. 7 to 10 days
d. 2 to 3 weeks
Early cardiac manifestations appear 7 to 10 days after viral infection.