Drowning and sudden cardiac death.

Drowning is one of the leading causes of accidental death in children. Some apparent drownings may be related to sudden cardiac death, in particular to unidentifi ed channelopathies, which are known to precipitate fatal arrhythmias during swimming-related events. In this article, the authors examine the likely incidence of such events, the impact of these events on the community, the cardiac defects involved and whether realistic and reliable measures are available to identify those at risk. In developed countries, drowning is the third leading cause of accidental childhood death with a mortality in the UK of 0.7/100 000 children <15 years.1 The death rate is higher in countries such as the USA and Australia where warmer climates lend themselves to more water exposure and higher numbers of domestic pools.1 2 Data from national agencies in the UK and Australia indicate that 40% of these drownings occur in swimming pools3 4 while reports from the USA demonstrate that 19% of drowning deaths in children occur in public pools with certifi ed lifeguards present.5 There is less information concerning morbidity, but it is estimated that for each drowning death, there are up to four non-fatal drowning events requiring hospitalisation.1 In almost all cases, these events are considered accidental; thus, extensive efforts have been made to reduce the potential for unsupervised and unsafe exposure of young children to water. Drowning rates have consequently declined over recent years predominantly due to these preventive efforts.6 However, despite these efforts, one report has recently highlighted that up to 50% of drownings occur in 5–19year-olds who were are least moderate swimmers.7 Numerous media reports have highlighted sudden demise in young children and adolescents during routine-monitored swimming lessons refl ecting high profi le cases of sudden deaths seen in athletes in various other sports. These cases have led to charges of negligence brought against lifeguards in swimming pools in the UK for not identifying those in trouble. Cases have been reported indicating that this may not be justifi ed. This includes the case of a reasonable swimmer in supervised swimming lessons in the shallow end of a swimming pool becoming motionless following diving relays and, despite full cardiopulmonary resuscitation for documented pulseless ventricular tachycardia, could not be resuscitated (personal experience). Such cases demonstrate that some apparent drownings may be related to a sudden cardiac event and as such are to some extent immune to the safety measures that have been implemented to date. Highlighting awareness of these conditions may be the fi rst step in limiting the misdiagnosis of some cases of accidental drowning and the consequences this may have on those involved, including family, due to the inheritable nature of these conditions.