While sports participation, including football, is a safe and enjoyable activity for the vast majority of individuals it can be potentially harmful for some people. There are a number of cardiac conditions that can predispose people to sudden cardiac arrest (SCA) and sudden cardiac death (SCD). These are frequently asymptomatic and as a result not identified in the athlete. In addition, secondary factors associated with sports activity such as electrolyte disturbances (particularly hypokalaemia and hypomagnesaemia), drug abuse, (over) activity of the autonomic nervous system and psychosocial factors which may trigger sudden cardiac arrest (SCA) or even sudden cardiac death (SCD) need to be considered.
The primary causes of SCA and SCD are lethal arrhythmias such as ventricular tachyarrhythmias, in particular ventricular fibrillation, while bradyarrhythmias or asystole are far less common. The latter are often due to the extension of a pathological process into the conduction system, causing complete heart block without a reliable escape focus. In addition, syncope may occur during exercise in certain congenital lesions with right-to-left shunts and cyanosis. This can also occur due to dissections of the great vessels, particularly in patients with Marfan syndrome, leading to pericardial tamponade or deleterious major internal bleeding.