On the monitor, a client's rhythm is irregularly irregular with a wavy baseline and no distinct P waves. Which rhythm is this?
Atrial fibrillation
✓
Atrial flutter
Ventricular tachycardia
Sinus tachycardia
Correct Answer
Atrial fibrillation
In atrial fibrillation, many atrial foci fire chaotically, so no organized P waves form and the baseline looks wavy; only some impulses pass the AV node, which makes the ventricular rhythm irregularly irregular. Atrial flutter shows regular sawtooth flutter waves. Ventricular tachycardia shows a run of wide QRS complexes. Sinus tachycardia is regular, with a P wave before every QRS.
Category: Dysrhythmia Basics
Question 2
A provider has a client with stable supraventricular tachycardia bear down as if having a bowel movement. How can this technique end the rhythm?
It blocks sodium channels in the ventricles
It increases vagal stimulation of the heart
✓
It increases sympathetic firing of the SA node
It raises the potassium level in the AV node
Correct Answer
It increases vagal stimulation of the heart
Bearing down is the Valsalva maneuver, a vagal maneuver that increases parasympathetic tone, slowing SA node pacing and AV node conduction. Blocking sodium channels in the ventricles is the action of class I drugs, not a vagal maneuver. Increasing sympathetic firing of the SA node would speed the heart. Raising the potassium level in the AV node is not how a vagal maneuver works.
Category: Dysrhythmia Basics
Question 3
A client receiving a QT-prolonging antidysrhythmic develops torsade de pointes. Which IV drug does the nurse anticipate to treat this rhythm?
Calcium gluconate
Adenosine
Magnesium sulfate
✓
Sodium bicarbonate
Correct Answer
Magnesium sulfate
IV magnesium sulfate is the standard drug treatment for torsade de pointes, even when the serum magnesium level is normal, and the drug that prolonged the QT interval is stopped; an unstable client is defibrillated. Calcium gluconate protects the heart in hyperkalemia but does not treat torsade de pointes. Adenosine ends supraventricular tachycardia and has no role in this ventricular rhythm. Sodium bicarbonate treats certain acid-base problems and overdoses, not torsade de pointes.
Category: Dysrhythmia Basics
Question 4
Why do class IA drugs such as quinidine prolong the QT interval more than class IC drugs do?
They also block beta-1 receptors
They also block calcium channels
They also stimulate vagal tone
They also block potassium channels
✓
Correct Answer
They also block potassium channels
Class IA drugs add potassium channel blockade to moderate sodium channel blockade, which prolongs repolarization and the QT interval and raises the risk of torsade de pointes. Class IC drugs block sodium strongly without potassium blockade. Blocking beta-1 receptors is the class II action. Blocking calcium channels is the class IV action. Stimulating vagal tone describes digoxin, not class IA drugs.
Category: Class I Sodium Blockers
Question 5
A client receiving IV procainamide develops joint pain, fever and a positive antinuclear antibody (ANA) titer. Which adverse effect does the nurse suspect?
Drug-induced lupus-like syndrome
✓
Serotonin syndrome
Stevens-Johnson syndrome
Neuroleptic malignant syndrome
Correct Answer
Drug-induced lupus-like syndrome
Procainamide carries a boxed warning for positive ANA titers, with or without a lupus-like syndrome of joint pain, fever and rash, and systemic lupus is a contraindication. Serotonin syndrome comes from excess serotonergic drugs. Stevens-Johnson syndrome is a severe blistering skin reaction. Neuroleptic malignant syndrome is linked to antipsychotics.
Category: Class I Sodium Blockers
Question 6
During an IV lidocaine infusion, a client becomes confused and develops muscle twitching. Which adverse effect should the nurse suspect?
Hypoglycemia
Central nervous system toxicity
✓
Hyperkalemia
Thyroid storm
Correct Answer
Central nervous system toxicity
Lidocaine toxicity shows up in the central nervous system as sedation, confusion, twitching, seizures and respiratory depression, so the nurse assesses neurologic status often during an infusion and reports changes at once. Hypoglycemia is not a typical lidocaine effect. Hyperkalemia is not caused by lidocaine. Thyroid storm is linked to hyperthyroidism, not to lidocaine.
Category: Class I Sodium Blockers
Question 7
As an antidysrhythmic, lidocaine is given IV for which type of rhythm disturbance?
Atrial fibrillation
Sinus bradycardia
Ventricular dysrhythmias
✓
Atrial flutter
Correct Answer
Ventricular dysrhythmias
Lidocaine, a class IB drug, produces mild sodium channel blockade and is given IV for ventricular dysrhythmias, including during advanced cardiac life support. Atrial fibrillation and atrial flutter are treated with other drug classes. Sinus bradycardia is not treated with lidocaine; symptomatic bradycardia is treated with atropine.
Category: Class I Sodium Blockers
Question 8
Flecainide is contraindicated in a client with which history?
Seasonal allergies
Migraine headaches
Hypothyroidism
Prior myocardial infarction
✓
Correct Answer
Prior myocardial infarction
Class IC drugs such as flecainide are contraindicated in structural heart disease, including prior myocardial infarction and heart failure, because a major trial showed excess deaths in clients taking them after a heart attack. Seasonal allergies do not affect flecainide use. Migraine headaches are not a contraindication. Hypothyroidism is not a listed contraindication.
Category: Class I Sodium Blockers
Question 9
A client with recurrent, symptomatic paroxysmal AF and no structural heart disease is told to take one dose of propafenone only when symptoms begin instead of every day. What is this strategy called?
Pill-in-the-pocket approach
✓
Drug holiday approach
Loading-dose approach
Step-down approach
Correct Answer
Pill-in-the-pocket approach
In the pill-in-the-pocket approach, the client carries the drug and takes a single dose when a paroxysmal episode starts, without daily dosing or a visit to the provider. A drug holiday approach is a planned break from a drug. A loading-dose approach gives a large first dose to reach a level quickly. A step-down approach lowers the dose or intensity over time.
Category: Class I Sodium Blockers
Question 10
How does metoprolol slow the heart rate in a client with a tachydysrhythmia?
It blocks beta-2 receptors in the lungs
It blocks beta-1 receptors in the heart
✓
It blocks alpha-1 receptors in vessels
It blocks muscarinic receptors in the heart
Correct Answer
It blocks beta-1 receptors in the heart
Metoprolol is a cardioselective beta-1 antagonist; blocking cardiac beta-1 receptors slows SA node firing and AV node conduction. Blocking beta-2 receptors in the lungs causes bronchospasm, not rate control. Blocking alpha-1 receptors in vessels causes vasodilation. Blocking muscarinic receptors in the heart, as atropine does, speeds the heart.
Category: Class II Beta Blockers
Question 11
The IV site of a client receiving an esmolol infusion is swollen, cool and painful. What should the nurse do first?
Speed up the infusion
Massage the site and continue
Stop the infusion at once
✓
Flush the line with saline
Correct Answer
Stop the infusion at once
Esmolol is a vesicant, and extravasation can cause skin necrosis and sloughing, so the nurse stops the infusion first, then aspirates the line and elevates the limb. Speeding up the infusion pushes more drug into the tissue. Massaging the site and continuing spreads the injury. Flushing the line with saline forces the drug further into the tissue.
Category: Class II Beta Blockers
Question 12
Before amiodarone is started for a life-threatening dysrhythmia, which baseline tests does the nurse expect?
Bone density scan
Audiometry hearing test
Colonoscopy screening
Chest x-ray and lung function tests
✓
Correct Answer
Chest x-ray and lung function tests
Amiodarone carries a boxed warning for pulmonary toxicity, so a baseline chest x-ray and pulmonary function tests are obtained and repeated during therapy, along with liver, thyroid and eye monitoring. A bone density scan is not part of amiodarone monitoring. An audiometry hearing test is not required. Colonoscopy screening is unrelated to the drug.
Category: Class III Potassium Blockers
Question 13
A client who takes oral propafenone calls to report a new fever and sore throat. Which adverse effect is the nurse concerned about?
Agranulocytosis
✓
Hypokalemia
Hyperglycemia
Angioedema
Correct Answer
Agranulocytosis
Propafenone can cause agranulocytosis, a dangerous loss of infection-fighting white blood cells, so clients are taught to report fever, sore throat or other signs of infection promptly and a blood count is checked. Hypokalemia causes muscle weakness and cramps rather than fever. Hyperglycemia causes thirst and frequent urination. Angioedema is swelling of the face, lips or tongue.
Category: Class I Sodium Blockers
Question 14
A client taking amiodarone reports heat intolerance, anxiety and weight loss. Which adverse effect do these findings suggest?
Hypothyroidism
Hyperthyroidism
✓
Hypoglycemia
Hypokalemia
Correct Answer
Hyperthyroidism
Amiodarone contains iodine and can cause either an overactive or an underactive thyroid; heat intolerance, anxiety and weight loss point to hyperthyroidism. Hypothyroidism causes fatigue, weight gain and cold sensitivity. Hypoglycemia causes shakiness, sweating and confusion rather than weight loss with heat intolerance. Hypokalemia causes muscle weakness and cramps.
Category: Class III Potassium Blockers
Question 15
Dofetilide must be started in a facility with continuous ECG monitoring and resuscitation available because of which risk?
Risk of pancreatitis
Risk of angioedema
Risk of torsade de pointes
✓
Risk of hypoglycemia
Correct Answer
Risk of torsade de pointes
Dofetilide is a pure potassium channel blocker that prolongs the QT interval, so its boxed warning requires starting it under continuous ECG monitoring where torsade de pointes can be treated. The risk of pancreatitis is not linked to dofetilide. The risk of angioedema is linked to ACE inhibitors. The risk of hypoglycemia is not a concern with dofetilide.
Category: Class III Potassium Blockers
Question 16
Which class III drug is given only IV, for short-term use, almost exclusively to convert recent-onset AF or atrial flutter to sinus rhythm?
Sotalol
Amiodarone
Dronedarone
Ibutilide
✓
Correct Answer
Ibutilide
Ibutilide is an IV-only pure class III drug used for acute conversion of recent-onset atrial fibrillation or flutter, with no long-term maintenance use, and the client stays on continuous ECG monitoring afterward. Sotalol is given orally or IV and is used for ongoing rhythm control. Amiodarone has an oral form for long-term therapy. Dronedarone is an oral drug for maintenance in atrial fibrillation.
Category: Class III Potassium Blockers
Question 17
Which antidysrhythmic is classified as a hazardous drug because it can harm a fetus, so the nurse wears gloves when handling it?
Dronedarone
✓
Lidocaine
Diltiazem
Metoprolol
Correct Answer
Dronedarone
Dronedarone is teratogenic, is contraindicated in pregnancy and is handled under hazardous-drug precautions such as wearing gloves. Lidocaine is a sodium channel blocker without this handling requirement. Diltiazem is a calcium channel blocker without this handling requirement. Metoprolol is a beta blocker without this handling requirement.
Category: Class III Potassium Blockers
Question 18
IV diltiazem is ordered for a client with AF with rapid ventricular response. What is the goal of this drug?
Converting the rhythm by blocking potassium channels
Slowing the ventricular rate by slowing AV conduction
✓
Raising blood pressure by increasing contractility
Preventing clots by inhibiting platelets
Correct Answer
Slowing the ventricular rate by slowing AV conduction
Diltiazem is a nondihydropyridine calcium channel blocker that slows conduction through the AV node, so fewer atrial impulses reach the ventricles and the ventricular rate falls. Converting the rhythm by blocking potassium channels is a class III action. Raising blood pressure by increasing contractility is the opposite of its effect, since it lowers both. Preventing clots by inhibiting platelets is the job of antiplatelet drugs.
Category: Class IV Calcium Blockers
Question 19
A client who takes a beta blocker is started on diltiazem. Which combined effect should the nurse monitor for?
Hyperkalemia
Hypoglycemia
Bradycardia and AV block
✓
Ototoxicity
Correct Answer
Bradycardia and AV block
Beta blockers and nondihydropyridine calcium channel blockers both slow the SA node and AV conduction, so together they can cause excessive slowing and heart block; heart rate and blood pressure are checked before each dose. Hyperkalemia is not an expected result of this combination. Hypoglycemia is not caused by diltiazem. Ototoxicity is linked to drugs such as aminoglycosides and loop diuretics.
Category: Class IV Calcium Blockers
Question 20
How should the nurse give IV atropine for symptomatic bradycardia?
Slowly, to prevent flushing
As a continuous infusion
Into the deltoid muscle
Rapidly, since a slow push can slow the heart
✓
Correct Answer
Rapidly, since a slow push can slow the heart
Atropine blocks vagal effects on the heart and is given by rapid IV injection, because slow administration has been linked to paradoxical bradycardia. Giving it slowly risks that paradoxical slowing and is not done to prevent flushing. A continuous infusion is not how atropine is given for bradycardia. Injecting into the deltoid muscle is too slow and unreliable for an unstable cardiac rhythm.
Category: Unclassified Antidysrhythmics