ACLS Tachycardia and Bradycardia Algorithms 2 — Questions and Answers
Question 1: A patient has a heart rate of 160 bpm with a narrow QRS complex and is hemodynamically stable. What is the first-line treatment?
- Immediate synchronized cardioversion
- Vagal maneuvers (Correct answer)
- Adenosine 12 mg IV push
- Amiodarone 150 mg IV over 10 minutes
Correct answer: Vagal maneuvers
Vagal maneuvers (e.g., Valsalva, carotid sinus massage) are the first-line treatment for stable narrow-complex tachycardia.
Question 2: During the bradycardia algorithm, atropine fails to increase the heart rate. What is the next intervention?
- Repeat atropine 1 mg IV
- Transcutaneous pacing or dopamine/epinephrine infusion (Correct answer)
- Synchronized cardioversion
- Adenosine 6 mg IV push
Correct answer: Transcutaneous pacing or dopamine/epinephrine infusion
If atropine is ineffective for symptomatic bradycardia, transcutaneous pacing or vasopressor infusion (dopamine or epinephrine) should be initiated.
Question 3: A 58-year-old patient has a heart rate of 190 bpm with a wide QRS complex and is pulseless. What is the correct action?
- Synchronized cardioversion at 120 J
- Adenosine 6 mg IV push
- Defibrillation and CPR per VF/pVT algorithm (Correct answer)
- Amiodarone 300 mg IV bolus
Correct answer: Defibrillation and CPR per VF/pVT algorithm
A pulseless wide-complex tachycardia is treated as ventricular fibrillation/pulseless VT — defibrillation and CPR per cardiac arrest algorithm.
Question 4: Which of the following is NOT a sign of hemodynamic instability requiring immediate intervention in tachycardia?
- Hypotension (BP < 90 mmHg)
- Altered mental status
- Heart rate of 110 bpm at rest (Correct answer)
- Acute pulmonary edema
Correct answer: Heart rate of 110 bpm at rest
A heart rate of 110 bpm alone does not constitute instability; signs like hypotension, altered mentation, and pulmonary edema indicate instability.
Question 5: What is the maximum total dose of atropine recommended in the ACLS bradycardia algorithm?
- 1 mg
- 2 mg
- 3 mg (Correct answer)
- 5 mg
Correct answer: 3 mg
The maximum total dose of atropine in the ACLS bradycardia algorithm is 3 mg (given as 0.5 mg doses every 3–5 minutes).
Question 6: A patient presents with atrial fibrillation with rapid ventricular response at 145 bpm, BP 88/60. What is the most appropriate next step?
- Rate control with diltiazem IV
- Anticoagulation with heparin
- Synchronized cardioversion (Correct answer)
- Rhythm control with oral flecainide
Correct answer: Synchronized cardioversion
Hemodynamically unstable atrial fibrillation with rapid ventricular response requires immediate synchronized cardioversion.
Question 7: Which energy setting is recommended for synchronized cardioversion of atrial flutter?
- 50–100 J (Correct answer)
- 120–200 J
- 200 J
- 360 J
Correct answer: 50–100 J
Atrial flutter typically responds to lower energy levels (50–100 J) for synchronized cardioversion compared to atrial fibrillation.
ACLS Tachycardia and Bradycardia Algorithms 2
A patient has a heart rate of 160 bpm with a narrow QRS complex and is hemodynamically stable.
What is the first-line treatment?