Summary

Methaemoglobinaemia is rare. Acute myocardial infarction (AMI) is common. The authors present a unique case of methaemaglobinaemia masquerading as an AMI. A middle-aged male was urgently referred to a tertiary cardiac centre for primary percutaneous coronary intervention with acute chest pain, cyanosis and tachycardia. However, on arrival, his ECG was felt to be within normal limits. Similarly unremarkable, were his echocardiogram and routine blood tests. Arterial blood gas analysis revealed a methaemaglobinaemia of 28.5% which normalised spontaneously. This was thought to be secondary to the use of smelling salts, inhaled earlier that day in the gymnasium. This is the first reported case of smelling salts inducing methaemaglobinaemia and of methaemaglobinaemia mimicking an AMI.