Shockable Arrest: VF & pVT
Objective: Fine or coarse VF and pulseless VT are shockable. Defibrillate, resume CPR immediately, keep pauses short, and do not miss fine VF by calling asystole.
Why This Is Hard
The shockable pathway is simple on a poster and messy on a bedroom floor. People pause to stare, argue about pad placement, or “charge while we check” for 20 seconds. Coronary perfusion pressure falls every time compressions stop. Fine VF gets called asystole (see that lesson). Your job is a repeatable shock-CPR cycle.
The Cycle (Education)
- Confirm arrest. High-quality CPR while the defibrillator charges if your system does so.
- Clear, shock VF/pVT at protocol energy, immediately resume CPR — do not check a pulse after the shock until the next planned rhythm check.
- Minimize peri-shock pauses. Charge during compressions if trained and the device allows.
- Airway and epinephrine timing follow your arrest protocol; they do not outrank defibrillation and CPR quality in shockable arrest.
- If the screen looks flat: gain, pads, second view — fine VF is still shockable.
What Not to Freestyle
- AHA 2025: after three or more consecutive shocks, the usefulness of vector-change defibrillation and double sequential defibrillation (DSD) has not been established (Class 2b). That is not a first-shock or first-line move. Use it only if your protocol and medical direction include it for refractory VF/pVT.
- Do not stacked-shock without CPR unless your current protocol still says so (modern teaching is shock → immediately resume CPR).
- Do not shock asystole “just in case.”
- VF or pVT — shockable
- Clear → shock → immediate CPR
- Next rhythm check on the planned cycle — not after every joule
- DSD / vector-change only if protocol after refractory shocks
Field Pitfalls
- Long “is that coarse enough?” pauses.
- Pulse checks after every shock instead of after a full CPR interval.
- Wet or hairy chests so pads never dump energy into the heart.
Practice
60-second drill
In CardioStrip Compare mode, open fine VF next to coarse VF. Both are shockable. Then run one cycle out loud: CPR → charge → clear → shock → immediate CPR (no pulse check until the next planned rhythm check).
Related: Asystole vs Fine VF, ROSC & Post-Arrest Care.
Sources & Further Study
Named guidelines for further study. They are not clinical orders and do not replace your protocol or medical direction.
- AHA 2025 Adult Advanced Life Support (CPR & ECC Part 9)
- VF and pulseless VT are shockable. Immediate CPR after the shock, short peri-shock pauses, high-quality compressions. DSD/vector-change usefulness has not been established (Class 2b after ≥3 shocks) — protocol only.
Education only. Apply learning within your protocols and medical direction. This is not clinical care guidance.
Check Your Understanding
Street decisions from this lesson only. After you check, the key is highlighted. Education practice — not a certification exam.