Biphasic and monophasic waveforms have been used for defibrillation. Older defibrillators deliver monophasic waveforms while newer ones deliver biphasic waveform.
Most intravascular magnetic resonance systems need an intravascular probe and an external MRI scanner, though newer stand alone probes are being developed.
Automatic external defibrillator (AED) can analyse cardiac rhythm and deliver a shock if the rhythm is ventricular fibrillation or ventricular tachycardia.
Chain of survival is a four link chain used to illustrate the importance of timely actions for the survival of victims of sudden cardiac arrest due to VF.