Chapter 45- Antiarrhythmic Agents
The nurse assesses the patient's rhythm strip and notes several premature ventricular contractions, which the nurse recognizes is caused by what? A) Stimulation of the ventricles from an ectopic focus in the ventricles B) Stimulation of the ventricles from the atrioventricular node C) Stimulation of the ventricles from the Purkinje fibers D) Stimulation of the ventricles from the bundle of His
Ans: A Feedback: Premature ventricular contractions are stimulations of the cells caused by an ectopic focus in the ventricles causing an early contraction. The source of these ectopic foci could be anywhere within the ventricles, but the end result is reduced cardiac output due to reduced force of contraction.
A nurse is caring for a patient who has had disopyramide (Norpace), ordered. Before administering disopyramide (Norpace) what is the nurse's priority action to maintain safety? A) Offer the patient something to drink. B) Ask the patient if he or she needs to void. C) Raise all side rails. D) Place the call button within reach.
Ans: C Feedback: When administering disopyramide, the nurse should make sure that all side-rails are up. The central nervous system effects of the drug can include dizziness, drowsiness, fatigue, twitching, mouth numbness, slurred speech, vision changes, and tremors that can progress to convulsions. The other three options are appropriate and placing the call button within reach can also be considered a safety measure; however nothing has a higher priority than raising the bed's side-rails.
The nurse is providing drug teaching about quinidine in preparation for the patient's discharge. The nurse discusses drug-food interactions and advises the patient to drink what? A) Apple juice B) Grapefruit juice C) Milk D) Orange juice
Ans: A Feedback: Apple juice would be the best choice. Quinidine requires a slightly acidic urine (normal state) for excretion. Patients receiving quinidine should avoid foods that alkalinize the urine (e.g., citrus juices, vegetables, antacids, milk products), which could lead to increased quinidine levels and toxicity. Grapefruit juice has been shown to interfere with the metabolism of quinidine, leading to increased serum levels and toxic effects; this combination should be avoided.
The nurse reviews the patient's medical history and determines class II antiarrhythmics are contraindicated due to the patient's history of what condition? A) Asthma B) Colitis C) Migraine headache D) Antidiarrheals
Ans: A Feedback: Class II antiarrhythmics are contraindicated in patients with asthma because they could worsen the condition due to blockage of beta-receptors. They are not contraindicated in patients with colitis, migraine headache, or diarrhea.
The nurse performs an electrocardiogram and finds the older adult patient is in atrial fibrillation (AF). Time of onset is unknown but could be as long as 3 months earlier when the patient was last assessed. What drug will the nurse expect to be ordered? A) Anticoagulant B) Digoxin C) Quinidine D) Ibutilide
Ans: A Feedback: If the onset of AF is not known and it is suspected that the atria may have been fibrillating for longer than 1 week, the patient is better off staying in AF without drug therapy or electrocardioversion. Prophylactic oral anticoagulants are given to decrease the risk of clot formation and emboli being pumped into the system. In 2011, the American Heart Association and American College of Cardiology endorsed dabigatran (Pradaxa) as the anticoagulant of choice for prophylaxis in AF. Conversion in this case could result in potentially life-threatening embolization of the lungs, brain, or other tissues. Administration of other antiarrhythmics would not be indicated.
The nurse is providing drug teaching for a patient who is to be discharged taking dofetilide (Tikosyn). What drug will the nurse teach the patient to avoid due to a drug-drug interaction? A) Cimetidine B) Furosemide C) Acetaminophen D) Antacids
Ans: A Feedback: There is an increased risk of serious adverse effects if dofetilide is combined with ketoconazole, cimetidine, or verapamil, so these combinations should be avoided. There is no known increased risk associated with furosemide, acetaminophen, or antacids but other specific drug-drug interaction are reported, so it is important to check a current drug handbook before administering these medications.
A patient with impaired renal function is to receive dofetilide (Tikosyn) for conversion of atrial fibrillation. What is the nurse's priority assessment before administering the drug? A) Check the patient's creatinine level. B) Measure the urine output. C) Listen to breath sounds. D) Measure the PR interval on the electrocardiogram.
Ans: A Feedback: When giving dofetilide to a patient with renal dysfunction, the dosage must be calculated according to the patient's creatinine level to ensure the therapeutic effect while limiting toxicity. This drug can only be administered by oral route. Intake and output as well as breath sounds may need to be assessed but are not related to administering the drug. A patient in atrial fibrillation will not have a measurable PR interval.
The nurse is teaching a class for newly hired cardiac care nurses and is discussing dronedarone (Multaq). What statement, if made by the nurse, is accurate? (Select all that apply.) A) "Dronedarone has properties of all four classes of antiarrhythmics." B) "Dronedarone reduces the risk of hospitalization in patients in atrial fibrillation." C) "Dronedarone has many drug-drug interactions that need to be reviewed." D) "It is an oral drug taken once a day." E) "Common adverse effects of dronedarone include ventricular arrhythmias."
Ans: A, B, C Feedback: Dronedarone has properties of all four classes of antiarrhythmics and the mechanism by which it helps suppress atrial arrhythmias is not fully understood. It is used to reduce the risk of hospitalization in patients with paroxysmal or persistent atrial fibrillation or flutter who have risk factors for cardiovascular disease and who are in sinus rhythm or are scheduled to be converted to sinus rhythm. The drug is taken orally twice a day. Many drug-drug interactions have been associated with the drug and this situation should always be reviewed before starting or stopping any drugs while on this drug. Grapefruit juice should not be consumed while taking this drug. The most common adverse effects seen with dronedarone are heart failure, prolonged QT interval, nausea, diarrhea, and rash. It should never be used during pregnancy because it has been associated with fetal abnormalities.
The emergency department nurse is administering IV lidocaine to a patient. What adverse effect of lidocaine therapy should the nurse assess for? A) Dysphagia B) Dizziness C) Excessive bruising D) Tinnitus
Ans: B Feedback: Adverse effects include dizziness, light-headedness, fatigue, arrhythmias, cardiac arrest, nausea, vomiting, anaphylactoid reactions, hypotension, and vasodilation. Dysphagia, bruising, and tinnitus are not usually associated with lidocaine.
The nurse is administering an intravenous infusion of amiodarone (Cordarone). What should the nurse be aware of? A) The possible drug-drug interaction with nonsteroidal anti-inflammatory drugs (NSAIDs) B) The possible development of very serious cardiac arrhythmias C) The possible development of peripheral edema D) The possible development of a fatal renal toxicity
Ans: B Feedback: Amiodarone has been associated with a potentially fatal liver toxicity rather than a renal toxicity, ocular abnormalities, and the development of very serious cardiac arrhythmias. Sotalol may have a loss of effectiveness if combined with NSAIDs. Diltiazem is associated with peripheral edema.
What class of antiarrhythmic agent would the nurse be most likely to administer to a lactating new mother? A) Class Ib B) Class II C) Class III D) Class IV
Ans: B Feedback: Class I, III, and IV agents should not be used during lactation; if they are needed, another method of feeding the baby should be used. This leaves only class II drugs for consideration if the mother is lactating.
What class of antiarrhythmics will the nurse administer to the patient in symptomatic paroxysmal tachycardia because it markedly depresses phase 0 with extreme slowing of conduction? A) Class Ib B) Class Ic C) Class II D) Class III
Ans: B Feedback: Class Ic drugs markedly depress phase 0, with a resultant extreme slowing of conduction, but have little effect on the duration of the action potential. As a result, they are indicated for the treatment of paroxysmal tachycardia. Class Ib drugs depress phase 0 somewhat and actually shorten the duration of the action potential. The class II antiarrhythmics are beta-adrenergic blockers that block beta-receptors, causing a depression of phase 4 of the action potential. The class III antiarrhythmics block potassium channels and slow the outward movement of potassium during phase 3 of the action potential, thus prolonging it.
The nurse teaches the patient receiving propranolol (Inderal) at home for management of a ventricular dysrhythmia to monitor what parameter? A) Daily fluid intake B) Daily blood pressure C) Weekly weight D) Weekly pulse
Ans: B Feedback: Hypotension can occur with propranolol, which is a beta-blocker, so patients should check their blood pressure and pulse every day. Propranolol does not require that fluid intake be measured. propranolol also will not require daily weight taking, but it may be necessary with a diagnosis of propranolol.
The nurse suspects drug toxicity in the patient who has been receiving lidocaine by infusion over the past 2 days to control a ventricular arrhythmia. What assessment would the nurse perform to determine the accuracy of the suspicion of toxicity? A) Neurological assessment B) Serum lidocaine level C) Renal function studies D) Hepatic function studies
Ans: B Feedback: If lidocaine is used for ventricular arrhythmias related to cardiac surgery or digoxin toxicity, serum levels should be monitored regularly to determine the appropriate dose and to avoid the potential for serious proarrhythmias and other adverse effects. Neurological assessment may indicate adverse effects but would not confirm lidocaine toxicity. Renal and hepatic function would not confirm lidocaine toxicity.
The nurse administers a bolus of lidocaine and follows it with a continuous infusion at what rate? A) 0.25 to 0.75 mg/min B) 1 to 4 mg/min C) 6 to 8 mg/min D) 10 to 20 mg/min
Ans: B Feedback: Lidocaine may be delivered at 1 to 4 mg/min after a bolus. Therefore, the other options are incorrect.
The nurse is caring for a patient who takes an antiarrhythmic agent and is reporting a complete lack of appetite. Which cardiac antiarrhythmic agent would the nurse suspect the patient is taking? A) Diltiazem (Cardizem) B) Propranolol (Inderal) C) Lidocaine (Lidocaine Parenteral) D) Amiodarone (Cordarone)
Ans: B Feedback: Propranolol frequently causes gastrointestinal (GI) problems such as nausea, vomiting, anorexia, constipation, and diarrhea. Diltiazem could cause nausea and vomiting but would not cause anorexia. Lidocaine can lead to changes in taste, nausea, and vomiting but does not cause anorexia. Amiodarone has adverse effects including nausea, vomiting, GI distress, weakness, dizziness, hypotension, heart failure, arrhythmia, a potentially fatal liver toxicity, and ocular abnormalities but does not cause anorexia.
The patient asks the nurse, "Will I have to take this antiarrhythmic agent for the rest of my life?" The nurse, having reviewed the CAST study, responds by saying what? A) "Yes, you will have to take this drug for life." B) "The drug is indicated for short-term treatment of life-threatening ventricular arrhythmias." C) "This drug may need to be changed but you'll take an antiarrhythmic for life." D) "After the arrhythmia is corrected, the drug will be stopped."
Ans: B Feedback: The CAST study, a large research study run by the National Heart and Lung Institute, found that long-term treatment of arrhythmias may have an uncertain effect on mortality, and in some cases may actually lead to increased cardiac death, which is the basis for the current indication for antiarrhythmics to be used only short-term to treat life-threatening ventricular arrhythmias.
The nurse administers what drug to terminate supraventricular tachycardia? A) Lidocaine (Lidocaine Parenteral) B) Flecainide (Tambocor) C) Adenosine (Adenocard) D) Dronedarone (Multaq)
Ans: C Feedback: Adenosine depresses conduction at the atrioventricular node and is used to restore NSR (normal sinus rhythm) in patients with paroxysmal supraventricular tachycardia. Adenosine is used to treat supraventricular tachycardias, including those caused by the use of alternate conduction pathways in adults. Lidocaine is used to treat life-threatening ventricular arrhythmias during myocardial infarction or cardiac surgery; it is also used as a bolus injection in emergencies when monitoring is not available to document exact arrhythmia. Flecainide is used to treat life-threatening ventricular arrhythmias in adults; prevention of paroxysmal atrial tachycardia (PAT) in symptomatic patients with no structural heart defect. Dronedarone is used to treat paroxysmal or persistent atrial fibrillation or atrial flutter in patients with multiple risk factors for coronary artery disease who are currently in sinus rhythm or scheduled for conversion.
What patient factor would result in the nurse administering a reduced dosage of disopyramide (Norpace)? A) Dehydration B) Hypertension C) Renal impairment D) Chronic diarrhea
Ans: C Feedback: Caution should be used with renal or hepatic dysfunction, which could interfere with the biotransformation and excretion of these drugs. Caution is not indicated with the findings of dehydration, hypertension, or chronic diarrhea.
When the nurse is caring for a patient with a cardiac arrhythmia, the priority goal for the patient is what? A) To maintain nutritional intake B) To maintain fluid intake C) To maintain cardiac output D) To maintain urine output
Ans: C Feedback: Disruptions in the normal rhythm of the heart can interfere with myocardial contractions and affect the cardiac output, the amount of blood pumped with each beat. Arrhythmias that seriously disrupt cardiac output can be fatal. Therefore, the primary goal of treating a cardiac arrhythmia is to maintain adequate cardiac output to support life. The other goals may be important to individual patient care, but sustaining life takes priority.
What would the nurse teach the diabetic patient to monitor for when beginning a class II antidysrhythmic drug regimen in addition to insulin? A) Weight loss B) Reduced peripheral perfusion C) Hypoglycemia D) Exercise intolerance
Ans: C Feedback: Increased hypoglycemia is possible if these drugs are combined with insulin; so patients should be taught to monitor their blood sugar levels often. Recurrent hypoglycemic episodes may indicate the need to reduce insulin dosage, but this advice would need to come from the health care provider. Class II antiarrhythmic drugs are normally not associated with weight loss, reduced peripheral perfusion, or exercise intolerance.
For what condition would the nurse expect to administer lidocaine via IV drip? A) Decrease in arterial oxygen saturation (SaO2) B) Increase in blood pressure C) Multiple premature ventricular contractions (PVCs) D) Increase in intracranial pressure (ICP)
Ans: C Feedback: Lidocaine drips are indicated for the treatment of life-threatening ventricular arrhythmias such as long or frequent runs of PVCs. Lidocaine would not be indicated for the treatment of hypoxia, hypertension, or increased ICP.
What class of antiarrhythmics drug blocks potassium channels, prolonging phase 3 of the action potential and slowing the rate and conduction of the heart? A) I B) II C) III D) IV
Ans: C Feedback: The class III antiarrhythmics block potassium, prolonging phase 3 of the action potential, which prolongs repolarization and slows the rate and conduction of the heart. Class I drugs block the sodium channels in the cell membrane during an action potential. Class II drugs are beta-adrenergic blockers that block beta-receptors, causing a depression of phase 4 of the action potential. Class IV drugs block calcium channels in the cell membrane leading to a depression of depolarization and a prolongation of phases I and II of repolarization, which slows automaticity.
You are caring for a patient who takes an antiarrhythmic agent. What would be a priority nursing assessment before administering this drug? A) Assess mental status. B) Assess breath sounds. C) Assess pulses and blood pressure. D) Assess urine output.
Ans: C Feedback: The nurse should continually monitor cardiac rate and rhythm when administering an antiarrhythmic agent to detect potentially serious adverse effects and to evaluate drug effectiveness. All of the other options are appropriate assessments but are not the priority assessment.
The nurse sees a patient in an outpatient setting who is given a new prescription for an antiarrhythmic medication to treat premature atrial contractions (PAC). The nurse has limited time with the patient and addresses what priority nursing diagnosis? A) Decreased cardiac output B) Alteration in comfort C) Deficient knowledge D) Potential for injury
Ans: C Feedback: The patient received a new prescription and needs information about how to take the medication, when to call the provider, and potential adverse effects so the priority nursing diagnosis is deficient knowledge. It is unknown what arrhythmia the patient is treating and without this information it is impossible to know what the impact on cardiac output, comfort and potential for injury may be.
A patient has had sotalol (Betapace) ordered for treatment of a ventricular arrhythmia. What will the nurse consider when administering the drug? A) Sotalol has a very short duration of action B) Food increases the bioavailability of the drug C) Absorption of sotalol is decreased by the presence of food D) The drug is best administered intramuscularly
Ans: C Feedback: This drug should not be taken with food because absorption is decreased. The drug should be given 1 hour before or 2 hours after a meal. Adenosine, not sotalol, has a very short duration of action and food increases the bioavailability of propranolol. Sotalol is administered by oral route only.
A 92-year-old patient is being sent home on disopyramide (Norpace) for a ventricular arrhythmia. He asks the nurse why he must continue to take this drug. The nurse's best response would be that failure to treat a ventricular arrhythmia may what? A) Lead to renal failure B) Result in hypertension C) Result in death D) Cause heart failure
Ans: C Feedback: Ventricular arrhythmias cause a dramatic reduction in cardiac output and will result in death if not treated. The patient needs to be taught the importance of taking his medication every day as ordered. Generally, ventricular arrhythmias are not associated with renal failure, hypertension, or heart failure.
The nurse is caring for a patient receiving propranolol. What problems, reported by the patient, does the nurse suspect is caused by the drug? (Select all that apply.) A) Seizures B) Rash C) Atrioventricular (AV) block D) Bronchospasm E) Dreams
Ans: C, D, E Feedback: The adverse effects associated with class II antiarrhythmics are related to the effects of blocking beta-receptors in the sympathetic nervous system. Central nervous system effects include dizziness, insomnia, unusual dreams, and fatigue. Cardiovascular symptoms can include hypotension, bradycardia, AV block, arrhythmias, and alterations in peripheral perfusion. Respiratory effects can include bronchospasm and dyspnea. GI problems frequently include nausea, vomiting, anorexia, constipation, and diarrhea. Other effects to anticipate include a loss of libido, decreased exercise tolerance, and alterations in blood glucose levels. Seizures and rash are not usually associated with the adverse effects of propranolol.
What nursing assessment will the nurse perform to determine the hemodynamic effect of the patient's arrhythmia? A) Obtain an electrocardiographic rhythm strip. B) Obtain a serum drug level. C) Assess the patient's level of consciousness. D) Assess the patient's blood pressure (BP) and pulse rate.
Ans: D Feedback: BP and pulse rate are indicators of the hemodynamic effect of arrhythmias and are nursing measures that do not require a physician's order. Obtaining an electrocardiogram or checking drug levels requires a physician's order. The patient will be conscious and alert with non-life-threatening arrhythmias, even when cardiac output is reduced. Serum drug levels would indicate the therapeutic or toxic level of drugs in the body but would not indicate hemodynamic effects of the drug.
The nurse is caring for a patient who reports insomnia since starting the antiarrhythmic agent prescribed for him or her. What antiarrhythmic agent would the nurse expect this patient is taking? A) Disopyramide (Norpace) B) Amiodarone (Cordarone) C) Procainamide (Pronestyl) D) Propranolol (Inderal)
Ans: D Feedback: Class II antiarrhythmics can cause insomnia. The adverse effects associated with class II antiarrhythmics are related to the effects of blocking beta-receptors in the sympathetic nervous system. CNS effects include dizziness, insomnia, unusual dreams, and fatigue. Disopyramide and procainamide are class I agents and do not cause insomnia. Amiodarone is a class III drug and is not associated with insomnia.
A patient with a history of atrial fibrillation has had a worsening of his or her condition. The nurse knows that the drug of choice for long-term stabilization of atrial fibrillation following electrocardioversion is what? A) Disopyramide (Norpace) B) Moricizine (Ethmozine) C) Procainamide (Pronestyl) D) Quinidine (generic)
Ans: D Feedback: Quinidine is often the drug of choice for long-term stabilization of atrial fibrillation after the rhythm is converted by electrocardioversion. Quinidine is a class I antiarrhythmic and stabilizes the cell membrane by binding to sodium channels, depressing phase 0 of the action potential, and changing the duration of the action potential. Disopyramide, moricizine, and procainamide are all used in the treatment of life-threatening ventricular arrhythmias.
What class of antiarrhythmic agents does the nurse administer to depress generation of the action potentials and delaying phases 1 and 2 of repolarization? A) Class Ib B) Class II C) Class III D) Class IV
Ans: D Feedback: The class IV antiarrhythmics block the movement of calcium ions across the cell membrane, depressing the generation of action potentials and delaying phases 1 and 2 of repolarization, which slows automaticity and conduction. Class Ib drugs depress phase 0 somewhat and actually shorten the duration of the action potential. The class II antiarrhythmics are beta-adrenergic blockers that block beta-receptors, causing a depression of phase 4 of the action potential. The class III antiarrhythmics block potassium channels and slow the outward movement of potassium during phase 3 of the action potential, thus prolonging it.
The nurse is caring for a pediatric patient who has been diagnosed with paroxysmal atrial tachycardia. The order reads digoxin 10 mcg/kg orally. The child weighs 44 pounds. How many mcg will the nurse administer? A) 50 mcg B) 100 mcg C) 150 mcg D) 200 mcg
Ans: D Feedback: The nurse will administer 200 mcg. (2.2 pounds: 1 kg = X: 20 kg, 20(10) = 200 mcg).
The nurse is caring for a 3-year-old awaiting a heart transplant who requires an antiarrhythmic agent to control a supraventricular arrhythmia. What drug, if ordered, would the nurse question? A) Digoxin B) Propranolol C) Procainamide D) Verapamil
Ans: D Feedback: Verapamil should be avoided in children and, if ordered, would require the nurse to question the drug. Adenosine, propranolol, procainamide, and digoxin have been successfully used to treat supraventricular arrhythmias, with propranolol and digoxin being the drugs of choice for long-term management.
What class of antiarrhythmic agents does the nurse administer to slow the outward movement of potassium during phase 3 of the action potential? A) Class Ib B) Class Ic C) Class II D) Class III
What class of antiarrhythmic agents does the nurse administer to slow the outward movement of potassium during phase 3 of the action potential? A) Class Ib B) Class Ic C) Class II D) Class III
