Pressure Volume Loop

The investigators are doing this study and medical record review to measure simultaneous pressure and volume of the heart called pressure volumes loops before and after ventricular assist device placement for cardiogenic shock ( a severe form of heart failure). Standard of care measurements will be the sole measure of clinical determination. The investigators are measuring these PV loops to help determine which patients heart have recovered and can have the ventricular assist device removed. The investigators are also using the PV loop to indicate/correlate with certain outcomes to predict the need for LVAD patients to require additional support in the form of a right ventricular assist device. The medical record review will be performed pre-operatively, intra-operatively, and post-operatively until the day of discharge.