Figure 1. Baseline Period.

In high-resolution manometry with esophageal pressure topography, pressure is assessed in relation to time and distance. Pressure is displayed as a heat map with dark blue representing lower pressures and higher pressures colored red to purple. The horizontal axis represents time. In this window, time is displayed in 10 second intervals; zooming in or out will change the time interval. The vertical axis represents distance and each black circle corresponds to a pressure sensor. In this window distance is portrayed as cm from the nares; clicking on ‘Fr. Nares’ can change the display to represent cm from the lower esophageal sphincter (LES) or sensor number.

In this window, the interpreter is clicked into the baseline period, as represented by the red frame. There are two high-pressure zones corresponding to the upper esophageal sphincter (UES) and lower esophageal sphincter (LES). As depicted by the yellow boxes, the corresponding markers are positioned to reflect UES and LES (proximal and distal border). In addition, the gastric marker is positioned at least 2cm below the distal border of the LES and in this particular case is positioned distal to the hiatus hernia. The pressure inversion point (PIP) is identified (purple box labeled PIP). The separation between the crural diaphragm (CD) and the LES is assessed; in this case, it is estimated at 5.7 cm consistent with a type III esophagogastric junction morphology. (Esophageal pressure topography plot reproduced with permission from the Esophageal Center at Northwestern Medicine Digestive Health Center.)