To monitor the cardiac post-op patient population with both the pulmonary artery catheter (PAC) and the Caretaker monitor, which will seek to validate the Caretaker monitor against continuous CO via the PAC. Up to a third of post-operative cardiac surgery patients develop cardiac arrhythmias such as atrial flutter and atrial fibrillation. Secondary analysis will be performed on the collected data to assess the Caretaker monitor's agreement with the PAC during periods of arrhythmia. Successful completion this study will provide clinical validation of the Caretaker monitor in one of the most hemodynamically challenging patient populations (post-cardiac surgery patients in the ICU), including during arrhythmias. The Caretaker monitor is most beneficial as it is non-invasive, is a minimal risk device, and for this protocol will not be utilized to make treatment decisions for the study subject. This device also does not project energy into the subject.

Up to a third of post-operative cardiac surgery patients develop cardiac arrhythmias such as atrial flutter and atrial fibrillation. Secondary analysis will be performed on the collected data to assess the Caretaker monitor's agreement with the PAC during periods of arrhythmia. Successful completion this study will provide clinical validation of the Caretaker monitor in one of the most hemodynamically challenging patient populations (post-cardiac surgery patients in the ICU), including during arrhythmias. The Caretaker monitor is most beneficial as it is non-invasive, is a minimal risk device, and for this protocol will not be utilized to make treatment decisions for the study subject. This device also does not project energy into the subject.

Inclusion:

• Adult post-cardiac surgery needing cardiopulmonary bypass and use of the PAC as standard of care, (s/p Coronary artery bypass graft surgery (CABG), valve, heart transplant, major aortic & other vascular surgery, and a combination of CABG and valve procedures)
• patients (age > 18) admitted to the Intensive Care Unit (ICU)
• Pulmonary artery catheter (continuous or intermittent thermodilution cardiac output) and an arterial catheter for Blood Pressure monitoring (standard of care)

Exclusion:

• Patients without an appropriately positioned or functioning PA catheter admitted to the cardiac surgery ICU after surgery
• Patients on left ventricular assist device (LVAD) support

Adult post-cardiac surgery needing cardiopulmonary bypass and use of the PAC as standard of care, (s/p CABG, valve, heart transplant, major aortic & other vascular surgery, and a combination of CABG and valve procedures)