Speaker: Professor Michael Shattock, School of Cardiovascular Medicine and Sciences, King's College London

Do all drowning victims drown? This talk describes the evidence that sudden cold water immersion is an environmental trigger for lethal cardiac arrhythmias. Sudden cold-water immersion causes ECG changes and runs of tachy- and brady-cardia that are common in healthy people (and dolphins!). These dysrhythmias may reflect sudden antagonism between the sympathetic and parasympathetic input to the heart - autonomic conflict. This autonomic conflict is benign in healthy individuals but dangerous when combined with other predisposing factors.