In ventricular fibrillation (VF) or pulseless ventricular tachycardia (VT), up to three stacked shocks should be given without intervening external chest compressions.IB
Thereafter, a single attempt at defibrillation, if required, is performed every 2 min.IC
If the arrhythmia is due to an acute coronary artery occlusion, repeat shock administration can be deferred to facilitate percutaneous coronary intervention (PCI) to the occluded artery.IIaC
Shocks for known VF/VT should be administered while mechanical cardiopulmonary resuscitation (CPR) is ongoing.IC
If the patient is receiving mechanical CPR and it is possible to assess the rhythm while the CPR is ongoing then it may not be necessary to pause the CPR device.IIaC