Chapter 25- Drug Therapy for Dysrhythmias

1. A nurse is teaching a cardiac patient about the ability of the heart to generate an electrical impulse. Which of the following teaching points should the nurse convey to the patient?

1. A)  “There are many different parts of your heart that can initiate an electrical

   impulse.”

2. B)  “Electrical signals travel along the blood vessels that provide oxygen to your

   heart.”

3. C)  “Your heart depends on your brainstem to initiate electrical signals.”
4. D)  “The lining of your left ventricle is the site where electrical signals usually

   originate.”

Ans: A

Feedback:

Any part of the conduction system can spontaneously start an impulse, but the sinoatrial (SA) node normally has the fastest rate of automaticity and therefore the faster rate of spontaneous impulse formation. The SA node is located in the right atrium. The brain does not initiate the electrical signal. Conduction does not exclusively follow blood vessels.

2. A patient is administered medications for the treatment of a rapid dysrhythmia. What is the mechanism of action for these medications?

1. A)  Reducing automaticity
2. B)  Increasing conduction
3. C)  Repolarizing myocardial cells
4. D)  Reducing refractory period

Ans: A Feedback:

Drugs used for the treatment of rapid dysrhythmias mainly reduce automaticity. They slow the conduction of electrical impulses through the heart. They spontaneously depolarize myocardial cells. They prolong the refractory period of myocardial cells.

3. A patient is being treated with quinidine to reduce automaticity. The nurse should advocate for a lower-than-normal dose if the patient has a history of

1. A)  type 1 or type 2 diabetes.
2. B)  primary hypertension.
3. C)  liver disease.
4. D)  chronic obstructive pulmonary disease.

Ans: C
Feedback:
Hepatic impairment increases the plasma half-life of several antidysrhythmic drugs, including quinidine, and patients with hepatic impairment usually receive a reduced dosage.

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4. A patient has been prescribed disopyramide (Norpace) to treat chronic ventricular tachycardia. The nurse’s subsequent cardiac assessments and monitoring should be planned in the knowledge that this drug has the potential to cause what health problem?

1. A)  New-onset chest pain
2. B)  Mitral valve regurgitation
3. C)  Acute renal failure
4. D)  New dysrhythmias

Ans: C

Feedback:

For disopyramide, the Food and Drug Administration (FDA) has issued a black box warning because of the drug’s known prodysrhythmic properties. It is not specifically linked to chest pain, valvular regurgitation, or renal failure.

5. A patient is admitted to the emergency room with a ventricular dysrhythmia associated with an acute myocardial infarction. The physician has ordered a bolus of lidocaine IV. What assessment should the nurse make prior to administering this medication?

1. A)  Assess for lidocaine administration in the patient’s history.
2. B)  Determine the patient’s ability to swallow.
3. C)  Assess the patient’s nutritional history for allergies.
4. D)  Determine if the patient has had a reaction to local anesthesia.

Ans: D
Feedback:
Lidocaine is contraindicated in patients allergic to local anesthetic agents. It is important to determine if the patient has been administered lidocaine in the past, but it is imperative to ascertain any untoward effects. The medication will be administered intravenously, so it is not necessary to assess the patient’s ability to swallow. However, swallowing can be impaired after administration and should be assessed. It is not necessary to do a nutritional assessment at this time.

6. A physician has ordered lidocaine IV for a patient with a ventricular dysrhythmia. The nurse has administered a bolus of lidocaine. What is the recommended rate for continuous infusion of lidocaine IV?

1. A)  0.25 to 0.75 mg/min
2. B)  10 to 20 mg/min
3. C)  1 to 4 mg/min
4. D)  6 to 8 mg/min

Ans: C

Feedback:

A continuous infusion of lidocaine IV after a bolus is 1 to 4 mg/min. The administration of 0.25 to 0.75 mg/min would be too small of a dosage. The administration of 10 to 20 or 6 to 8 mg/min would be too large.