Description

A 17-year-old male patient presented to the emergency department with sudden onset of palpitations after drinking high caffeine preparations at the gym. He had no relevant medical history or family history of sudden cardiac death. He denied any use of regular medications, alcohol or illicit drugs.

On arrival, he was tachycardic (ECG in figure 1—top) but haemodynamically stable. Cardiovascular examination was otherwise unremarkable; chest X-ray and routine blood tests were normal. He was given intravenous metoprolol with no significant effect. Subsequently, his blood pressure deteriorated (ECG in figure 1—bottom) and intravenous adenosine was administered followed by further blood pressure reduction. The on-call cardiologist was …