A 54 year old male patient presents to A&E complaining of central chest pain that has been present for 30 minutes. It was his birthday yesterday and he went to an Indian restaurant with his friends and had four pints of beer with his food. He initially took some Gaviscon, which alleviated the pain for a few minutes. He tells you that his left leg and hand feel a little strange but it could be linked to the change in weather exacerbating his arthritis. His past medical history includes type 2 diabetes, irritable bowel syndrome and arthritis. What is the most likely diagnosis?