NREMT Paramedic Cognitive ExamCardiology & ResuscitationEasy
A 30-year-old male presents with palpitations, lightheadedness, and a heart rate of 190 bpm. His ECG shows a regular narrow-complex tachycardia. He is alert and oriented, and his blood pressure is 110/70 mmHg. After attempting vagal maneuvers, which of the following is the most appropriate next intervention?
- AAdminister synchronized cardioversion at 50 J.
- BAdminister amiodarone 150 mg IV over 10 minutes.
- CAdminister metoprolol 5 mg IV.
- DAdminister adenosine 6 mg IV push.
Show answer & explanationAnswer & explanation
Correct answer: D. Administer adenosine 6 mg IV push.
The patient has a stable, regular narrow-complex tachycardia (likely SVT) that is symptomatic (palpitations, lightheadedness) but hemodynamically stable. After vagal maneuvers fail, adenosine is the first-line medication for such rhythms, as it temporarily blocks the AV node to diagnose and often terminate SVT.
Why the other options are wrong
- A. Synchronized cardioversion is for unstable tachycardias or when adenosine fails in stable SVT.
- B. Amiodarone is an antiarrhythmic typically used for rhythm control in AFib or for wide-complex tachycardias, not first-line for stable narrow-complex SVT.
- C. Metoprolol (a beta-blocker) can be used, but adenosine is generally preferred as the first-line agent for acute termination of SVT.
Stable Narrow-Complex Tachycardia Management
Stable narrow-complex tachycardia (often SVT) is a rapid heart rhythm originating above the ventricles, with QRS duration < 0.12 seconds, where the patient is hemodynamically stable.
- Commonly presents with palpitations, lightheadedness, anxiety.
- First-line intervention: Vagal maneuvers (Valsalva, carotid sinus massage).
- If vagal maneuvers fail, adenosine is the drug of choice.
- Beta-blockers or calcium channel blockers can also be used.
Memory trick: Fast and Stable? Vagal, then Adenosine's the Label!