47-year-old male smoker with a family history and previous history of ischaemic heart disease, presents with s 4-month history of increasing exertional chest pain and a 4-hour history of persistent, severe pain at rest, which is unrelieved by GTN and associated with nausea, vomiting, and sweating. On examination, he has a resting tachycardia and evidence of left ventricular dilatation with a displaced apex beat and possible secondary mitral regurgitation. The most likely diagnosis is acute myocardial infarction.