Inclusion Criteria:  Patients (18 years of age or older) Onset of distributive shock within 48 hours after heart transplantation or VAD placement. Distributive shock defined as MAP less than 55mmHg on CPB, MAP less than 70mmHg before or after CPB, or systemic vascular resistance (SVR) less than 800 dynes/cm/sec5 with cardiac index (CI) greater than 2.0L/min/m2 and clinically determined euvolemia.  Exclusion Criteria:  Patients without distributive shock, Women who are pregnant or breastfeeding. Patients who do not receive the study drug as a first line agent for distributive shock Allergy to angiotensin II, angiotensin II or another vasopressor being used at the time of presentation to the operating room Preexisting distributive shock Preexisting thromboembolic disease Patients who are unwilling to provide consent