A 70-Year-Old Woman With a Prosthetic Mitral Valve and Sudden Chest Pain.

A 70-year-old woman presented to the ED with oppressive ongoing chest pain that had lasted for 1 hour and was accompanied by intense sweating. The patient had a previous history of bronchial asthma, severe degenerative mitral regurgitation, and an ostium secundum atrial septal defect that had been treated 6 years ago with a prosthetic mechanical mitral valve, Bicarbon 25, and an atrial septal defect closure. She was being treated with ciclesonide, tiotropium bromide, olodaterol, theophylline, and warfarin, adjusted according to the international normalized ratio. Two weeks before the current event, because of trauma suffered in her leg, her primary care physician changed her treatment to subcutaneous enoxaparin, 80 mg once daily. Considering that her weight was 80 kg and her renal function was normal, the dose of enoxaparin prescribed was subtherapeutic for a mechanical prosthetic valve.