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The nurse is interpreting an ECG strip to determine whether there is a delay in impulse conduction above the ventricles. Which of the following components of an ECG strip should the nurse measure?
- A. P-wave
- B. P-R interval
- C. Q-T interval
- D. QRS complex
Correct Answer: B
Rationale: The P-R interval represents depolarization of the atria, atrioventricular (AV) node, bundle of His, bundle branches, and the Purkinje fibres. The QRS represents ventricular depolarization. The Q-T interval represents depolarization and repolarization of the entire conduction system.
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The nurse is caring for a patient who is on the telemetry unit and develops atrial flutter, rate 150, with associated dyspnea and diaphoresis, with an oxygen saturation of 94%. Which of the following actions that are included in the hospital dysrhythmia protocol should the nurse take first?
- A. Obtain a 12-lead electrocardiogram (ECG).
- B. Give O2 via nasal cannula at 3-4 L/minute.
- C. Take the patient's blood pressure and respiratory rate.
- D. Notify the health care provider of the change in rhythm.
Correct Answer: B
Rationale: Since this patient has dyspnea in association with the new rhythm, the nurse's initial actions should be to ensure a patent airway and oxygen administration. The other actions also are important and should be implemented rapidly.
The nurse administers IV atropine to a patient with symptomatic type 1, second-degree atrioventricular (AV) block. Which of the following findings indicate that the medication has been effective?
- A. Increase in the patient's heart rate
- B. Decrease in premature contractions
- C. Increase in peripheral pulse volume
- D. Decrease in ventricular ectopic beats
Correct Answer: A
Rationale: 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 ventricular ectopy or premature contractions.
The nurse is caring for a patient who has a ST segment change that indicates an acute inferior wall myocardial infarction. Which of the following leads is best for monitoring the patient?
- A. I
- B. II
- C. V6
- D. MCL1
Correct Answer: B
Rationale: Lead II reflects the inferior area of the heart that is experiencing the ST segment changes and will best reflect any electrocardiographic changes that indicate further damage to the myocardium. The other leads do not reflect the inferior part of the myocardial wall and will not provide data about further ischemic changes.
The nurse has received change-of-shift report about the following patients on the telemetry unit. Which of the following patients should the nurse see first?
- A. A patient with atrial fibrillation, rate 88, who has a new order for warfarin
- B. A patient with type 1 second-degree atrioventricular (AV) block, rate 60, who is dizzy when ambulating
- C. A patient who is in a sinus rhythm, rate 98, after having electrical cardioversion 2 hours ago
- D. A patient whose implantable cardioverter-defibrillator (ICD) fired three times today who has a dose of amiodarone due
Correct Answer: D
Rationale: The frequent firing of the ICD indicates that the patient's ventricles are very irritable, and the priority is to assess the patient and administer the amiodarone. The other patients may be seen after the amiodarone is administered.
A patient has a junctional escape rhythm on the monitor. The nurse will expect the patient to have a heart rate of how many beats/minute?
- A. 20-30
- B. 40-60
- C. 70-80
- D. 90-100
Correct Answer: B
Rationale: If the sinoatrial (SA) node fails to discharge, the atrioventricular (AV) node will automatically discharge at the normal rate of 40-60. 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 nodes to discharge. The normal SA node rate is 60-100 beats/minute.