ACLS Bradycardia 5 — Questions and Answers
Question 1: A 70-year-old patient on digoxin presents with bradycardia and nausea. Digoxin toxicity is suspected. Which intervention is MOST specific to this cause?
- Atropine 1 mg IV
- Transcutaneous pacing
- Digoxin-specific antibody fragments (Digibind) (Correct answer)
- Calcium chloride 1 g IV
Correct answer: Digoxin-specific antibody fragments (Digibind)
Digoxin-specific antibody fragments (Digibind/DigiFab) are the definitive antidote for life-threatening digoxin toxicity.
Question 2: A patient with a permanent pacemaker is found to have a heart rate of 35 bpm. The ECG shows no pacing spikes. What is the most likely problem?
- Battery depletion or pacemaker failure (Correct answer)
- Oversensing of muscle artifact
- Inappropriate rate response activation
- Normal pacemaker inhibition by intrinsic rhythm
Correct answer: Battery depletion or pacemaker failure
Absence of pacing spikes in a pacemaker-dependent patient with extreme bradycardia suggests battery depletion or device failure.
Question 3: Which of the following calcium channel blockers is most commonly associated with causing bradycardia and AV block?
- Amlodipine
- Nifedipine
- Verapamil (Correct answer)
- Nicardipine
Correct answer: Verapamil
Verapamil (a non-dihydropyridine calcium channel blocker) significantly slows AV conduction and can cause bradycardia and heart block.
Question 4: After giving atropine for symptomatic bradycardia with no improvement, the provider initiates dopamine at 5 mcg/kg/min. The patient's heart rate rises to 72 bpm and BP improves. What should be done next?
- Immediately increase dopamine to 20 mcg/kg/min
- Arrange for expert consultation and possible transvenous pacing (Correct answer)
- Discontinue dopamine and give atropine again
- Perform synchronized cardioversion
Correct answer: Arrange for expert consultation and possible transvenous pacing
A patient stabilized on a dopamine infusion still requires expert consultation to determine the need for transvenous pacing or other definitive treatment.
Question 5: A patient presents with complete heart block. On the ECG, the ventricular escape rate is 25 bpm and QRS complexes are wide. Which statement is most accurate?
- Atropine will reliably increase the ventricular rate
- This rhythm indicates an infranodal block and requires pacing (Correct answer)
- Adenosine should be given to restore normal conduction
- This is a benign rhythm that can be observed
Correct answer: This rhythm indicates an infranodal block and requires pacing
A slow wide-complex escape rhythm in complete heart block indicates infranodal block, which does not respond to atropine and requires pacing.
Question 6: Which of the following best describes 'pacemaker-mediated tachycardia' that can complicate dual-chamber pacemaker therapy?
- Rapid pacing caused by battery failure
- A reentrant tachycardia where the pacemaker participates in the circuit (Correct answer)
- Atrial fibrillation triggered by pacing
- Ventricular fibrillation due to pacing on the T wave
Correct answer: A reentrant tachycardia where the pacemaker participates in the circuit
Pacemaker-mediated tachycardia is a reentrant loop where retrograde conduction through the AV node is sensed by the atrial lead and triggers repetitive ventricular pacing.
Question 7: An athlete with symptomatic bradycardia (HR 36 bpm) is found to have high vagal tone as the cause. Which statement about this scenario is most accurate in the ACLS context?
- Atropine is contraindicated in athletes
- If symptomatic, treatment follows the standard ACLS bradycardia algorithm regardless of cause (Correct answer)
- Transcutaneous pacing is never needed in vagal bradycardia
- Athletes should receive adenosine to differentiate vagal from cardiac causes
Correct answer: If symptomatic, treatment follows the standard ACLS bradycardia algorithm regardless of cause
Regardless of the underlying cause, if bradycardia produces hemodynamic compromise, the standard ACLS bradycardia algorithm applies.
ACLS Bradycardia 5
A 70-year-old patient on digoxin presents with bradycardia and nausea.
Digoxin toxicity is suspected.
Which intervention is MOST specific to this cause?