Figure 3.

HRM recording of EGJ pressure in an individual with the CD being only partially superimposed on the LES pressure signature; the LES-CD separation is 2 cm. This is indeterminant for hiatus hernia as one cannot confidently localize the LES during inspiration necessitating that is position be defined during expiration. Formatting of the figure is identical to that of Figure 2 with the dominant EGJ pressure profile highlighted by the black line (the 15 mmHg isobaric contour) and the PIP tool optimally positioned to isolate the RIP. The center of the LES and CD high pressure zones (white and black horizontal arrows, respectively) are isolated with the help of the isobaric contour tool and the separation between the two rounded off to the nearest cm. In this example, the RIP continues to localize toward the upper margin of the CD signal. This is particularly evident during the three deep breaths where the strongly negative intrathoracic pressure (deep blue) is seen to abut directly on the CD signal negating whatever LES pressure signal may have been above it. Figure used with permission from the Esophageal Center at Northwestern.