Provide direct nursing care to cardiovascular ICU patients, including those recovering immediately post-operatively from open-heart surgery, maintaining a 1:1 or 1:2 nurse-to-patient ratio on the ICU side. Transition and support patients as they move from ICU-level care to progressive/step-down level care within a mixed-acuity cardiovascular unit, with ratios of 1:3 or 1:4 on the step-down side.