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Ventricular fibrillation (fine)

Also called fine V-fib.

The same chaos at low amplitude. Fine V-fib can look almost flat, which is why a flat line is confirmed in a second lead before anyone calls it asystole.

A 6-second EKG rhythm strip showing Ventricular fibrillation (fine).
Ventricular fibrillation (fine), 6 seconds of strip. Each small box is 0.04 seconds and each large box is 0.20 seconds.

How to identify Ventricular fibrillation (fine)

Rate
None to count
Rhythm
Chaotic
P waves
None
PR interval
None
QRS
None, only low, disorganized waves
Clincher
Low-amplitude chaos that can pass for a flat line. Confirm a flat line in a second lead.

Rhythms it gets mistaken for

Treatment by certification level

Open your level. Treat the patient, not the strip.

Paramedic

Shockable arrest.

  • CPR, pads on. Defibrillate (unsynchronized): biphasic 120-200 J (the maximum if you do not know the device recommendation), monophasic 360 J.
  • Resume compressions immediately after the shock. No rhythm or pulse check first.
  • IV/IO access. Epinephrine 1 mg every 3-5 minutes, typically after the second shock.
  • Still shockable after a shock and epinephrine: amiodarone 300 mg IV/IO, then 150 mg if it persists. Lidocaine 1-1.5 mg/kg, then half that, is the alternative.
  • Two-minute cycles: rhythm check, shock if shockable. Waveform capnography throughout.
  • Look for and treat the cause: the H's and T's.
AEMT

Cardiac arrest: CPR, the AED, epinephrine.

  • High-quality CPR and the AED, exactly as at the EMT level. After every analysis, shock or no shock, compressions resume immediately.
  • IV or IO access.
  • Epinephrine 1 mg IV/IO every 3-5 minutes, typically started after the second shock.
  • Supraglottic airway and waveform capnography. EtCO2 under 10 mmHg means fix the compressions; an abrupt sustained rise suggests ROSC, confirmed at the scheduled rhythm check.

Manual defibrillation and antiarrhythmics (amiodarone, lidocaine) are Paramedic level. The AEMT's electrical therapy is the AED.

EMT

Cardiac arrest: CPR and the AED.

  • High-quality CPR, starting with compressions.
  • AED on as soon as it arrives.
  • The AED will advise a shock for this rhythm. Clear, shock, then resume compressions immediately without a pulse check.
  • Two minutes of CPR, then let the AED reanalyze. Check a pulse only at that scheduled rhythm check.

Could you pick out Ventricular fibrillation (fine) on a fresh strip? See how many rhythms you can identify in one minute.

Try the 60-second rhythm challenge