5.2 Tachycardia With a Pulse
Key Takeaways
- The first tachycardia branch is unstable versus stable.
- Unstable tachycardia with a pulse generally requires synchronized cardioversion.
- Stable regular narrow-complex tachycardia may allow vagal maneuvers and adenosine.
- Wide-complex tachycardia requires caution; avoid AV nodal blockers in dangerous wide or irregular patterns.
5.2 Tachycardia With a Pulse
Tachycardia questions reward a structured approach: assess the patient, identify instability, classify QRS width and regularity, choose cardioversion or medication, and avoid harmful shortcuts.
Current official baseline
The adult advanced life support guidance covers cardiac arrest rhythms, defibrillation, airway decisions, drugs, peri-arrest tachycardia and bradycardia, and termination decisions. Use the official AHA 2025 Adult Advanced Life Support Guidelines page when your course materials or training-center instructions differ from third-party summaries: AHA 2025 Adult Advanced Life Support Guidelines.
What you need to know
| Decision point | What to do |
|---|---|
| Unstable | Hypotension, shock, altered mental status, ischemic chest discomfort, or acute heart failure can make tachycardia unstable. Prepare synchronized cardioversion. |
| Stable narrow regular | Vagal maneuvers and adenosine can be appropriate for regular narrow-complex SVT when the patient is stable. |
| Wide complex | Treat wide-complex tachycardia carefully. In unstable WCT, synchronized cardioversion is recommended. |
| Irregular or polymorphic | Do not casually give adenosine, diltiazem, or verapamil to unstable, irregular, or polymorphic wide-complex rhythms. |
How this shows up on BLS/ACLS questions
BLS and ACLS items usually test priority. Read the patient state first: age, pulse status, breathing status, rhythm, stability, and number of rescuers. Then choose the action that protects perfusion, oxygenation, defibrillation timing, or the correct algorithm branch. If an answer sounds advanced but delays CPR, shock delivery, ventilation, or an urgent stability intervention, it is usually a distractor.
Scenario anchor
A patient with a rate of 190 has chest pain, hypotension, and altered mental status. The best next action is synchronized cardioversion, not a slow diagnostic workup.
Common traps
- Using adenosine for unstable tachycardia instead of cardioversion.
- Forgetting to synchronize a shock when the patient has a pulse.
- Giving verapamil or diltiazem in wide-complex tachycardia.
Study action
Write this section as a one-line rule in your own words, then test it with mixed questions from the BLS/ACLS practice bank. Do not review only the matching topic. Mix it with nearby branches so you can tell when the rule applies and when it does not. For example, compare respiratory arrest with a pulse against pulseless arrest, or compare unstable tachycardia against VF/pVT arrest. The exam rewards that discrimination more than memorizing isolated facts.
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