The investigators are interested in determining if there is a meaningful difference between two of the most commonly used medications used to improve the pumping function of the heart among critically ill patients admitted to the Coronary Care Unit (CCU) at the University of Ottawa Heart Institute (UOHI). To do this, the investigators will randomly assign patients who are felt to require use of these medications by their treating physicians to one of the two most commonly used agents in Canada: Milrinone or Dobutamine. Each patient will be closely monitored by their healthcare team, and their medication will be adjusted based on each patient's clinical status. Information from blood work (e.g. kidney and liver function, complete blood counts, and other markers of how effectively blood is circulating in the body), assessment of end-organ function (e.g. urine output, mentation), abnormal heart rhythms noted on monitoring and results of imaging studies (e.g. angiogram, echocardiograms.) will be collected for analysis. All patients will be followed for the duration of their hospital stay at UOHI.