The investigators will enroll 3 groups: Group 1: Patients with established WHO-2 diagnosis of PH undergoing open and interventional mitral valve procedures. Group 2: Patients with no PH undergoing open and interventional mitral valve procedures. Group 3: Patients with established diagnosis of WHO-1-4 groups of PH undergoing right heart catheterization. Groups 2 and 3 will serve as controls. All procedures will be performed at the main UAB Hospital cardiac surgical operating rooms and at the cardiac angiographic suites. The investigators will collect a total of 3 blood samples; the first sample will be obtained on arterial cannulation before the initiation of the intervention, the second sample will be collected upon the end of the procedure prior to leaving the procedure room, and the third sample will be collected on the day of discharge from the hospital. A comprehensive echocardiogram at the 3 corresponding time points of the blood samples obtained; before, and after the intervention and before discharge.
