"Zero reference" during cardiac catheterization.
Hemodynamic pressure measurements obtained during cardiac catheterization studies are calibrated to an arbitrary level where the pressure is considered zero. Despite the fundamental nature of the zero reference level, there is no standardized method for determination of "zero reference." A horizontal metal rod has been constructed to be level with the pressure transducer domes. With lateral radiographic viewing, the metal rod is adjusted to be level with the junction of the inferior vena cava and the right atrium. The technique is rapid, reliable, without risk and allows accurate comparison of hemodynamic data between patients and in the same patient longitudinally.
Blood Pressure↗