Patient: The patient is a 17-year-old male athlete in apparently good health. In the last 5∈years he was engaged in competitive cycling by training for about 20-25∈hours (h) per week, and achieved a national and international level. He was recently selected as member of the junior national team. Since a head trauma in early childhood he showed a nystagmus. No previous cardiac disease or known cardiovascular risk factors were present. The patient was free of medications and denied the intake of doping substances. Also his father and grandfather were internationally successful competitive cyclists. His close relatives had no known cases of premature (<50∈years) sudden cardiac death. His grandfather underwent coronary revascularization at the age of 67 and a pacemaker implantation at 73∈years.