b'Abnormal Heart Rhythms (Arrhythmias)Ventricular Fibrillation (VF)This is heart irritability where the heart cells are not stimulating or firing off in an organisedmanner. Blood is not being pumped around the body and the patient will become unconscious with no heart beat.Ventricular Tachycardia (VT)This is heart irritability where the heart cells stimulate or fire off prematurely.This results in a fast abnormal heart beat. The heart cannot refill well enough and the patient will become unconscious with no heart beat.Both conditions are lethal and ultimately result in cardiac arrest with death being imminent unless there is rapid intervention with defibrillation.Defibrillation is a controlled direct current electrical shock that is passed through the pacemaker (Sino-atrial node) of the heart to stimulate the heart cells to re-correct and take spontaneous control and start contractions.Immediate CPR is required to artificially keep the heart beating and distributing oxygenated blood. However, the heart must be defibrillated in order to return the electrical conduction system back to normal so the heart can beat spontaneously.There is no doubt, CPR is lifesaving but unfortunately outside of hospital only a few people survive even if effective CPR is applied quickly. The majority of collapsed cardiac arrests are due to lethal electrical heart rhythms of VF or VT.Asystole is characterised by the absence of any cardiac electrical activity.VF or VT can be reversed in many instances provided there is rapid intervention with CPR and defibrillation. Current statistics show that if CPR and defibrillation is delayed, the chances of survival reduce by approximately 10% for each minute the heart is stopped.Resuscitation 55'