22 questions

Bradycardia & Tachycardia

A patient has a heart rate of 38 with hypotension and altered mental status. What is the first-line drug?

  • a.Adenosine
  • b.Atropine✓
  • c.Amiodarone
  • d.Metoprolol

Atropine has been shown effective for symptomatic bradycardia in observational studies and is the first drug used; the other options are tachycardia or rate-slowing drugs.

Bradycardia & Tachycardia

A patient with wide-complex tachycardia has a pulse but is hypotensive and confused. The appropriate treatment is:

  • a.Unsynchronized defibrillation
  • b.Synchronized cardioversion✓
  • c.Adenosine only, then observe
  • d.No treatment; continue to observe

An unstable tachycardia WITH a pulse (hypotension, altered mental status, ischemic chest pain, or signs of shock) is treated with immediate synchronized cardioversion. Synchronization times the shock to the R wave to avoid delivering energy during the vulnerable T-wave period, which could induce VF. Unsynchronized defibrillation is reserved for pulseless VT/VF.

Bradycardia & Tachycardia

Atropine has failed to improve a patient's symptomatic bradycardia. Appropriate next steps include:

  • a.Pacing or an epinephrine drip✓
  • b.Defibrillate the patient
  • c.Adenosine 6 mg rapid IV push
  • d.Synchronized cardioversion

If atropine is ineffective, the 2025 Guidelines call transcutaneous pacing or agents that raise heart rate and blood pressure (such as epinephrine or dopamine) reasonable; the choice depends on experience and resources.

Bradycardia & Tachycardia

A patient has a heart rate of 38, blood pressure 76/40 and confusion. What is the first-line drug?

  • a.Atropine✓
  • b.Amiodarone
  • c.Adenosine
  • d.Diltiazem

Atropine has been shown effective for symptomatic bradycardia in observational studies; the other drugs treat tachycardias.

Bradycardia & Tachycardia

Atropine fails in unstable bradycardia. What is a reasonable next step?

  • a.Adenosine
  • b.Synchronized cardioversion
  • c.Verapamil
  • d.Transcutaneous pacing✓

If atropine is ineffective, transcutaneous pacing or agents that raise heart rate and blood pressure, such as epinephrine or dopamine, are reasonable alternatives.

Bradycardia & Tachycardia

What must be confirmed after starting transcutaneous pacing?

  • a.The rate is over 150
  • b.The patient is asleep
  • c.Only pacer spikes on the monitor
  • d.Mechanical capture with a pulse✓

The Guidelines highlight difficulty achieving and maintaining both electrical and mechanical capture, so perfusion must be confirmed, not just the monitor pattern.

Bradycardia & Tachycardia

A conscious patient needs transcutaneous pacing. What should the team anticipate?

  • a.Permanent pacemaker in the ED
  • b.Pain; sedation may be needed✓
  • c.Immediate need for intubation
  • d.No discomfort at all

Transcutaneous pacing is often painful in conscious patients and tolerance may require sedation; it bridges to transvenous pacing or definitive treatment.

Bradycardia & Tachycardia

An asymptomatic athlete has a heart rate of 44. What is appropriate?

  • a.Transcutaneous pacing
  • b.No treatment for the rate✓
  • c.Atropine to raise the rate
  • d.Epinephrine infusion

Bradycardia can be a normal finding in healthy adults and athletes; treatment is for symptomatic or unstable bradycardia.

Bradycardia & Tachycardia

A patient in stable, regular narrow-complex tachycardia fails a modified Valsalva. What is next?

  • a.Adenosine✓
  • b.Atropine
  • c.Epinephrine
  • d.Defibrillation

Adenosine has very high conversion rates for AV nodal and AV reentrant tachycardias and is used after vagal maneuvers fail in stable patients.

Bradycardia & Tachycardia

What energy should start synchronized cardioversion for unstable atrial fibrillation in 2025?

  • a.10 J
  • b.50 J
  • c.200 J✓
  • d.25 J

The 2025 Guidelines replaced the incremental low-energy approach with a recommendation to begin at 200 J for atrial fibrillation and flutter.

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Bradycardia & Tachycardia

A patient with wide-complex tachycardia has a systolic pressure of 74 mm Hg and is confused. What is indicated?

  • a.Immediate synchronized cardioversion✓
  • b.Atropine IV
  • c.Verapamil IV
  • d.Observation and fluids only

If the patient is unstable because of the WCT, such as systolic pressure below 80 mm Hg or altered mentation, immediate synchronized cardioversion is warranted.

Bradycardia & Tachycardia

Why is verapamil dangerous for a wide-complex tachycardia of ventricular origin?

  • a.It is too slow to work
  • b.It causes torsades only in children
  • c.It speeds the ventricular rate to 300
  • d.It can cause shock and arrest✓

Verapamil will not terminate a WCT of ventricular origin and may cause profound hypotension leading to shock and cardiac arrest.

Bradycardia & Tachycardia

A patient with pre-excited atrial fibrillation (WPW) is rapidly conducting. Which drug class should be avoided?

  • a.IV fluids
  • b.AV nodal blockers✓
  • c.Oxygen
  • d.Sedatives before cardioversion

AV nodal blockers such as digoxin, calcium channel antagonists, β-blockers or IV amiodarone may cause VF in pre-excited AF; cardioversion is recommended.

Bradycardia & Tachycardia

Which rate-control drug should be avoided in rapid AF with decompensated systolic heart failure?

  • a.Amiodarone
  • b.Diltiazem✓
  • c.Oxygen
  • d.Furosemide

Nondihydropyridine calcium channel blockers such as diltiazem may further decompensate patients with LV systolic dysfunction and heart failure; amiodarone is an alternative.

Bradycardia & Tachycardia

Sustained polymorphic VT with a pulse develops. What is the treatment?

  • a.Oral β-blocker
  • b.Adenosine and observation
  • c.Immediate defibrillation✓
  • d.Synchronized cardioversion at 50 J

The 2025 Guidelines recommend that all adults with sustained polymorphic VT receive immediate defibrillation, since it is always unstable.

Bradycardia & Tachycardia

What does the modified Valsalva maneuver achieve compared with the standard maneuver?

  • a.No difference at all
  • b.Conversion of VF
  • c.Guaranteed conversion
  • d.Up to about 50%✓

Standard Valsalva ends 20 to 30% of narrow-complex tachycardias, and modified techniques improve termination to up to 50%.

Bradycardia & Tachycardia

Why is carotid massage used with caution?

  • a.It can trigger stroke✓
  • b.It lowers blood sugar
  • c.It is painful for children
  • d.It always causes VF

When performing carotid massage, caution is advised because it can precipitate a stroke in patients with carotid atherosclerosis.

Bradycardia & Tachycardia

A patient in stable monomorphic VT receives an antiarrhythmic. What should be immediately available?

  • a.A pacemaker magnet
  • b.A cooling blanket
  • c.Oral potassium
  • d.A defibrillator✓

When antiarrhythmics are given for WCT, immediate defibrillator availability is encouraged because each drug may convert the rhythm to a faster, unstable form.

Bradycardia & Tachycardia

In symptomatic bradycardia with shock and no IV access, what may be started immediately?

  • a.Oral atropine
  • b.IM adenosine
  • c.Transcutaneous pacing✓
  • d.Cardioversion

For severe symptomatic bradycardia causing shock without IV or IO access, immediate transcutaneous pacing while access is pursued may be undertaken.

Bradycardia & Tachycardia

Which is an example of a reversible cause of bradycardia listed in the Guidelines?

  • a.A high fever from a cold
  • b.Hypoxemia✓
  • c.Hyperthermia from exercise
  • d.Normal sleep

Causes of symptomatic bradycardia include myocardial ischemia, hypoxemia, hypothyroidism, infection, electrolyte abnormalities, and medications or toxins.

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Bradycardia & Tachycardia

In patients with coronary artery disease, what total atropine dose does the FDA-approved label restrict to?

  • a.10 mg to 12 mg
  • b.No limit
  • c.0.1 mg
  • d.2 mg to 3 mg✓

The label restricts total atropine to 2 mg to 3 mg (maximum 0.03–0.04 mg/kg) in coronary artery disease to avoid atropine-induced tachycardia raising oxygen demand.

Bradycardia & Tachycardia

A patient has symptomatic bradycardia and a history of recent heart transplant. What alternatives exist if atropine does not help?

  • a.Cardioversion
  • b.Pacing or an epinephrine or dopamine infusion✓
  • c.Diltiazem
  • d.Adenosine

If atropine is ineffective, transcutaneous pacing or agents such as epinephrine or dopamine are reasonable, chosen by experience and resources.

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