ACLS Tachycardia and Bradycardia Algorithms 5 — Questions and Answers
Question 1: A patient has sinus bradycardia at 48 bpm but is awake, alert, with BP 118/76 and no symptoms. What is the correct ACLS management?
- Atropine 0.5 mg IV immediately
- Transcutaneous pacing
- Observation — no treatment required (Correct answer)
- Dopamine infusion at 5 mcg/kg/min
Correct answer: Observation — no treatment required
Asymptomatic bradycardia without hemodynamic compromise does not require intervention in the ACLS algorithm.
Question 2: Which of the following is a Class III indication (harmful) for adenosine in tachycardia management?
- Regular narrow-complex SVT
- Irregular wide-complex tachycardia consistent with pre-excited AF (Correct answer)
- Stable AVNRT after failed vagal maneuvers
- Diagnostic use for wide-complex tachycardia of uncertain etiology
Correct answer: Irregular wide-complex tachycardia consistent with pre-excited AF
Adenosine is potentially harmful in irregular wide-complex tachycardia (pre-excited AF/WPW) because it can precipitate ventricular fibrillation.
Question 3: What synchronized cardioversion energy is recommended for unstable monomorphic VT in ACLS?
- 50 J
- 100 J (Correct answer)
- 200 J
- 360 J
Correct answer: 100 J
Unstable monomorphic VT is cardioverted starting at 100 J with biphasic energy per ACLS guidelines.
Question 4: A patient with narrow-complex tachycardia receives adenosine 6 mg without effect. What is the next step?
- Proceed immediately to synchronized cardioversion
- Administer adenosine 12 mg IV rapid push (Correct answer)
- Administer amiodarone 150 mg IV over 10 minutes
- Apply carotid sinus massage
Correct answer: Administer adenosine 12 mg IV rapid push
If the initial 6 mg dose of adenosine fails, the next dose is 12 mg IV given as a rapid push, which may be repeated once.
Question 5: Which of the following statements about transcutaneous pacing (TCP) is correct?
- TCP should be attempted before atropine in unstable bradycardia
- TCP is painless for conscious patients
- TCP should be used while awaiting transvenous pacing for unstable bradycardia (Correct answer)
- TCP is contraindicated in third-degree heart block
Correct answer: TCP should be used while awaiting transvenous pacing for unstable bradycardia
TCP is a temporizing measure for unstable bradycardia while definitive transvenous pacing is arranged.
Question 6: In the ACLS tachycardia algorithm, which condition requires treatment regardless of symptoms due to inherent risk?
- Sinus tachycardia at 105 bpm
- Ventricular tachycardia at 200 bpm even if stable (Correct answer)
- Atrial fibrillation with ventricular rate of 90 bpm
- Junctional rhythm at 55 bpm
Correct answer: Ventricular tachycardia at 200 bpm even if stable
Ventricular tachycardia at high rates carries risk of deterioration to VF and warrants prompt treatment even in stable patients.
Question 7: A provider is managing a patient with tachycardia and suspects the rhythm is AF with aberrant conduction vs. VT. The patient is stable. What is the safest pharmacological approach?
- Verapamil, since it slows the ventricular rate safely
- Adenosine, which is safe and diagnostic for both rhythms
- Procainamide, which is effective for both SVT with aberrancy and VT (Correct answer)
- Digoxin, which works well for all wide-complex tachycardias
Correct answer: Procainamide, which is effective for both SVT with aberrancy and VT
Procainamide is effective for both SVT with aberrancy and VT, making it a safe choice when the diagnosis is uncertain in a stable patient.
ACLS Tachycardia and Bradycardia Algorithms 5
A patient has sinus bradycardia at 48 bpm but is awake, alert, with BP 118/76 and no symptoms.
What is the correct ACLS management?