A 32-year-old gentleman was admitted for moderate to severe chest pain that he experienced for one day. He is a non-smoker and has no known diabetes, hyperlipidaemia or hypertension. He has no history of effort angina and he exercises regularly with no problems. His chest pain was unexertional, relieved by sitting and was worse with deep breathing. Physical examination showed no evidence of heart failure. A rubbing sound was heard on auscultation. His ECG is shown in the Figure.