Figure 10.

Evaluation of peristalsis with the distal latency and contraction front velocity. (A) Distal esophageal spasm is characterized by normal lower esophageal sphincter relaxation and a short distal latency (< 4.5 seconds). It is arrival of the swallow-induced contraction in the distal esophagus too rapidly, producing a simultaneous contraction. (B) Rapid contraction is defined by a rapid contraction front velocity (> 9 cm/sec), normal distal latency (> 4.5 seconds) and normal integrated relaxation or residual pressure. The peristaltic pressure wave also meets criteria for weak peristalsis; that is, a wide gap at the transition zone produced by failure of peristalsis in the proximal smooth muscle esophagus. This might be the genesis of the measured rapid wave front velocity. Finally, the black arrow indicates a diaphragmatic contraction, so there is a large hiatal hernia. DL, distal latency; UES, upper esophageal sphincter; EGJ, esophagogastric junction; CFV, contraction front velocity; LES, lower esophageal sphincter.