Final answer:
The first step a CPCT should take when a patient has ventricular fibrillation is to perform defibrillation using an External Automated Defibrillator (EAD) to attempt to restore normal heart rhythm.
Step-by-step explanation:
When a patient presents with ventricular fibrillation, as indicated by an EKG tracing, the first action a Certified Patient Care Technician (CPCT) should take is to initiate life support measures immediately. The most appropriate and vital intervention is to perform defibrillation using an External Automated Defibrillator (EAD). This device delivers a controlled electric shock to the patient's heart, aiming to stop the erratic electrical activity and allow the heart's natural pacemaker, the sinoatrial (SA) node, to reestablish a normal sinus rhythm. Defibrillation should be performed as quickly as possible, as ventricular fibrillation can lead to brain death in a matter of minutes if not treated.