Float the pulmonary-artery catheter and watch the pressure waveform change chamber by chamber: RA (a/c/v waves) → RV (sharp upstroke, low diastole that ramps up) → PA (same systolic, diastolic step-up, dicrotic notch) → wedge (inflate the balloon for a damped LA tracing). Then read the hemodynamic profile — CVP, PA, PAWP and the derived CI, SVR, PVR — and load a shock state to interpret.