Upper esophageal sphincter and pharyngoesophageal motor function in infants with and without gastroesophageal reflux.

Upper esophageal sphincter and pharyngeal motor function were assessed in 16 infants with gastroesophageal reflux and 11 age-matched control infants. Resting upper esophageal sphincter pressure in gastroesophageal reflux infants was 26.6 +/- 10.0 cmH2O (means +/- SD) and was similar to that of control infants (28.9 +/- 10.0 cmH2O). Pharyngeal contraction amplitude, duration, and velocity were the same in control and reflux subjects. A minor degree of incoordination between pharyngeal contraction and upper esophageal sphincter relaxation was noted in 2 control subjects and 2 infants with gastroesophageal reflux. Esophageal acidification produced an increase in mean upper esophageal sphincter resting pressure of 10.0 cmH2O in controls and 11.1 cmH2O in reflux patients.