A standard defibrillator delivers between 20 to 40 amps during a shock.

A defibrillator delivers a controlled electrical current to restore normal heart rhythm during cardiac arrest. The amperage typically ranges from 20 to 40 amps, though this varies based on the specific device and energy setting. Modern defibrillators use biphasic waveforms, which are more efficient than older monophasic designs, allowing effective treatment with lower current.

Key Factors Affecting Defibrillator Amperage

  • Energy level setting (measured in joules)
  • Type of waveform (biphasic vs monophasic)
  • Patient size and impedance
  • Specific device model and manufacturer

Defibrillator Types and Their Typical Amperage

Defibrillator Type Typical Amperage Range Energy Setting
Manual External 20-40A 120-360J
Automated External (AED) 15-30A 150-360J
Implantable Cardioverter Defibrillator (ICD) 5-10A 10-40J

Why Amperage Matters in Defibrillation

The electrical current must be sufficient to depolarize the heart muscle and interrupt chaotic electrical activity. Too little current may be ineffective, while excessive current could cause tissue damage. The biphasic waveform technology used in modern devices achieves the necessary effect with lower amperage by reversing the current direction partway through the shock.