Heart failure (HF) is an enormous health burden affecting approximately 5.1 million people in the US and is the cause of 250,000 deaths each year. Approximately 50% of HF is caused by myocardial ischemia and requires immediate restoration of coronary blood flow to the affected myocardium. However, the success of reperfusion is partly limited by intramyocardial hemorrhage, which is the deposition of intravascular material into the myocardium. Hemorrhagic reperfusion injury has high prevalence and patients have a much greater risk of adverse left ventricular remodeling, risk of fatal arrhythmia, impaired systolic function and are hospitalized at a greater rate. Recent magnetic resonance imaging techniques have improved assessment of reperfusion injury, however, the association between MRI contrasts and reperfusion injury is highly unclear, and lacks specificity to IMH. Improved imaging of IMH and accurate knowledge about its spatial and temporal evolution may be essential for delivery of optimal medical therapy in patients and critical to identify patients most at risk for adverse ventricular remodeling. The overall goal is to investigate the magnetic properties of hemorrhage and develop MRI techniques with improved specificity to hemorrhage. New MRI techniques permit noninvasive assessment of the magnetic susceptibility of tissues and can target tissue iron. Therefore, the investigators hypothesize that MRI imaging of myocardial magnetic susceptibility can map hemorrhagic myocardium. The investigators will perform a longitudinal observational study in patients after reperfusion injury to validate these methods, compare the methods with conventional MR contrasts and develop MR methods for imaging humans.

Inclusion Criteria:

• Between the ages of 18 and 80
• Patients must be able to read and understand English
• Participants must sign the informed consent form
• Elevated and delayed peak creatine kinase-MB and troponin I (cTnI) and troponin T (cTnT) in blood serum,
• ST elevation detected on ECG

Exclusion Criteria:

• contraindications to cardiac MRI, including claustrophobia
• advanced renal disease (estimated glomerular filtration rate 30 mL/min) or hypersensitivity to gadolinium
• presence of a cardiac pacemaker or implanted cardiac cardioverter defibrillator
• pregnancy
• personal or family history of hypertrophic cardiomyopathy
• inability to provide informed consent
• history of seizure disorder

The study population specific to this project are ST-elevated myocardial infarction (STEMI) patients being treated with reperfusion therapy.