cardiolab logocardiolab

Ventricular Fibrillation

critical
Lead II
25 mm/s10 mm/mV
Heart rate
—
RR
—
QT
—

Ventricular Fibrillation

Completely disorganized ventricular electrical activity. No coordinated contraction occurs — the ventricles quiver ineffectively. There is no cardiac output.

Mechanism

Completely disorganized ventricular electrical activity. No coordinated contraction occurs — the ventricles quiver ineffectively. There is no cardiac output.

Findings· 2
  • Chaotic, irregular waveform with no identifiable P waves, QRS complexes, or T waves.
  • Amplitude may be coarse (early) or fine (late/agonal).
Clinical Impact

Cardiac arrest. Fatal within minutes without intervention. Requires immediate CPR and defibrillation. Every minute without defibrillation reduces survival by ~10%.

Differential· 2
Torsades de Pointes

Organized polymorphic VT with spindle shape vs completely chaotic fibrillation. Both need defibrillation.

Fine VFib vs Asystole

Very fine VFib can appear as flatline. Confirm in ≥2 leads and check connections.