Pre-clinical studies have indicated that, during a continuous infusion of intravenous perfluorocarbon-containing microbubbles, the ultrasonic power delivered from a diagnostic ultrasound transducer is capable of restoring microcirculatory flow and improving epicardial recanalization rates following acute coronary thrombotic occlusions. Since both diagnostic ultrasound and intravenous infusions of microbubbles are a Class I indication to assess regional and global left ventricular function and risk area in patients with ST segment elevation myocardial infarction (STEMI), this pilot study will examine whether diagnostic assessments of left ventricular function and risk area size impacts epicardial recanalization rates and infarct size in STEMI.