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. Author manuscript; available in PMC: 2023 Dec 4.
Published in final edited form as: Eur J Gastroenterol Hepatol. 2020 Feb;32(2):166–174. doi: 10.1097/MEG.0000000000001584

Fig. 1.

Fig. 1.

Recording of pharyngeal reflux. (a) Representative example of a dual pH sensor catheter placing. The pH sensors were located 1 cm above the UES and 5 cm above the LES. Impedance electrodes are located 1 cm above and 2, 5 and 7 cm below the proximal pH sensor and 1 cm above and 1 and 3 cm below the distal pH sensor. (b) Representative trace of pharyngeal acidic reflux episode recorded by simultaneous pharyngeal and distal esophageal pH/impedance. Sudden drop of pH and impedance in the distal esophagus (black arrow, GER) is followed by distal to proximal decrease in impedance (distal to proximal movement of the refluxate) and subsequent drop of pH in the pharyngeal pH sensor (red arrow, pharyngeal reflux). GER, gastroesophageal reflux; LES, lower esophageal sphincter; UES, Upper esophageal sphincter..