New technologies in the gastrointestinal clinic and research: Impedance and high-resolution manometry

Figure 2 Typical swallow pressure topography spanning from the pharynx (locations 0-2 cm) to stomach (locations 29-35 cm) of a normal subject with normal peristalsis and normal EGJ relaxation. The transition zone, demarcating the end of the proximal esophageal segment (striated muscle) and the beginning of the distal esophageal segment (smooth muscle), is readily identified as a pressure minimum. Note that the distal segment, in fact, has three sub-segments (S1, S2, S3) within it, each with an identifiable pressure peak. Sub-segment 3, the LES, contracts at the termination of peristalsis and then descends back to the level of the CD as the period of swallow-related esophageal shortening ends. The onset of the deglutitive relaxation window is at the onset of upper sphincter relaxation while the offset is 10 s later. The spatial domain within which EGJ relaxation is assessed (the eSleeve™ range) is user defined, spanning at least 6 cm, depending on the extent of esophageal shortening after the swallow. The contractile front velocity (CFV) is the slope of the line connecting the black circle-points on the 30 mmHg isobaric contour at the proximal margin of S1 and the distal margin of S2.