ABSTRACT
A previously healthy 61-year-old man presented to the emergency department with chest pain and dyspnoea for 6 hours. Examination revealed distress with an apical pansystolic murmur. Initial electrocardiogram showed sinus tachycardia and ST elevation in leads II, III, and aVF compatible with an inferior ST-elevation myocardial infarction. Point-of-care echocardiography in the emergency department showed a flail anterior mitral leaflet and severe mitral regurgitation, leading to a provisional diagnosis of papillary muscle rupture. Emergency cardiac catheterization showed 100%, 80%, and 70% occlusion of the middle right coronary, left anterior descending, and left circumflex arteries, respectively. An emergency triple vessel coronary artery bypass grafting and mitral valve replacement was performed. Posteromedial papillary muscle rupture resulting in mitral regurgitation was confirmed intraoperatively. The patient recovered uneventfully. In the absence of primary percutaneous coronary intervention, thrombolysis decisions should be made with extreme caution if mechanical complications of ST-elevation myocardial infarction are suspected.