DYNAMIC CHARACTERISTICS OF GASTROESOPHAGEAL REFLUX IN AMBULATORY PATIENTS WITH GASTROESOPHAGEAL REFLUX DISEASE AND NORMAL CONTROL SUBJECTS

Background: The aim of the study was to investigate the dynamic charac teristics of pathologic gastrooesophageal reflux. Methods: Five-channe l ambulatory 24-h oesophageal pH monitoring was performed in 19 gastro -oesophageal reflux disease patients (age, 21-74 years) and in 19 heal thy volunteers (age, 21-64 years). The pH was recorded at 3, 6, 9, 12, and 15 cm from the lower oesophageal sphincter (LOS), using a sample frequency of 4 Hz for each channel. Automated analysis included calcul ation of the ascending velocity of the refluxate and duration and exte nt (cm above the LOS) of all individual reflux episodes. Results: In t he patients more upright reflux episodes reached the proximal sensor t han in the controls (20% and 11%, respectively, P < 0.01). The duratio n of the reflux episodes (measured at 3 cm above the LOS) was longer i n the patients than in controls (P < 0.0001). This effect was independ ent of the proximal extent of the reflux episodes. Ascending velocitie s of upright acid reflux were higher in controls (1.8 to 2.7 cm/sec) t han in patients (0.7 to 2.2 cm/sec; P = 0.01). Conclusions: The dynami c characteristics of pathologic reflux differ significantly from those of physiologic reflux.