4.3 VF and Pulseless VT Algorithm
Key Takeaways
- VF/pVT treatment centers on CPR, early defibrillation, repeated rhythm checks, epinephrine, antiarrhythmics, and reversible causes.
- Defibrillation should happen as soon as the shockable rhythm is identified and the team is clear.
- Resume CPR immediately after shock delivery.
- Drug timing matters, but drugs do not replace CPR and defibrillation.
4.3 VF and Pulseless VT Algorithm
The VF/pVT algorithm is the highest-yield ACLS cardiac arrest pathway. Candidates should know the loop and the priority order well enough to run it without reading the card box by box.
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 |
|---|---|
| First shock | When VF/pVT is identified, charge and shock quickly while minimizing time away from compressions. |
| CPR cycles | After shock, resume CPR immediately and continue the cycle before the next rhythm check. |
| Epinephrine | Use epinephrine during ongoing arrest according to the algorithm timing taught in your course. |
| Antiarrhythmics | For refractory VF/pVT, amiodarone or lidocaine may be used according to ACLS guidance and local protocol. |
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
After two shocks for VF, the rhythm remains VF. The team should resume CPR, continue algorithm timing, prepare epinephrine/antiarrhythmic therapy as indicated, and keep searching for reversible causes.
Common traps
- Waiting for a pulse check immediately after shock.
- Giving antiarrhythmics before the team has delivered early shocks and CPR.
- Forgetting pad contact, pad position, and compressor quality in refractory VF.
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.
Which of the following is a "T" in the Hs and Ts reversible causes of cardiac arrest?
A patient presents with confirmed pulmonary embolism and is in pulseless cardiac arrest (PEA). What additional intervention should be STRONGLY considered?