**1. Introduction**

Sudden cardiac death (SCD) remains a major global public health problem, especially in developed countries such as the United States of America (USA), United Kingdom (UK), Germany and other countries. Moreover, SCD is also the most common cause of death worldwide, accounting for >50% of all cardiovascular disease (CVD)-related deaths. SCD is characterized by unexpected loss of the

pumping action of the heart due to a disturbance in its electrical system that results in irregular and dangerously fast beating of the heart [1]. The ventricles may flutter or quiver (ventricular fibrillation), disrupting the pumping action of the myocardium, thereby stopping blood flow to the body. The blood flow to the brain is a matter of grave concern for the patients since reduced oxygenated blood supply to the brain can lead to unconsciousness and permanent damage to the brain. As such, death can follow unless the patient receives emergency treatment [2, 3]. Therefore, time is extremely critical when someone or a clinician is helping an unconscious person whose heart is not pumping (no pulse). SCD represents a major challenge for the clinician especially in individuals without a previous history of cardiac diseases. Early prediction of individuals at risk of SCD can be life-saving. Currently, most individuals experiencing SCD may not be identified as being a high risk and as such, the patients do not have ready access to a defibrillator. As a result, there must be community-based public access to defibrillation programmes in order to save the lives of the potential victims. SCD seems to occur most frequently in adults in their mid-30s to mid-40s and during working age, affecting both men and women. With SCD, some patients experience tachycardia, dizziness and fainting while in some cases there are no prior symptoms [4, 5].
