Proximal and distal esophageal contractions have similar manometric features

The human esophagus is composed of striated muscle proximally and of smooth muscle distally with a transition zone between the two. Striated muscle contracts much faster than smooth muscle. The change in pressure over time (dP/dt) of the contraction amplitude should therefore be higher in proximal than in distal esophagus, reflecting the presence of striated muscle proximally. There were 34 normal esophageal manometries of patients analyzed for swallow amplitude and dP/dt in the pharynx and esophagus. An additional 11 healthy controls were similarly studied. Amplitudes in pharynx and proximal and distal esophagus were not different. The mid-esophagus had a pressure trough (P < 0.001). The dP/dt in the pharynx was much higher than that in the esophagus (P < 0.001). The dP/dt of proximal and distal esophagus were of the same order of magnitude. The manometric behavior of the striated muscle portion of the proximal esophagus differs from that seen in the pharynx and shows similar characteristics to distal esophageal smooth muscle.