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Esophageal peristalsis consists of a chain of relaxing sphincters and contracting segments. First, the segment of skeletal muscle (S1) contracts, then the proximal segment of smooth muscle (S2), and finally the distal segment of smooth muscle (S3).1 The esophageal hypercontractility disorder has been postulated to be caused by imbalance between esophageal contraction and relaxation. A variant of this disorder, where contraction amplitudes of S3 are disproportionately exaggerated compared with those of S2, can produce esophageal symptoms.2 However, some of these contraction patterns could be averaged out and may not be registered as abnormal. Therefore, Mello et al3 tried to determine the clinical significance of these contraction patterns and the diagnostic sensitivity of Chicago classification for these patterns. The authors found that merged segments were in 5.6%, and exaggerated S3 in another 12.5%, but only 17?50% had a Chicago classification diagnosis. The cohorts with merged segments and exaggerated S3 had significantly higher proportions of abnormal relaxation of esophageal body during multiple rapid swallowing (MRS) (P < 0.005 for each comparison) and presenting symptoms (chest pain and dysphagia, P = 0.040) than healthy controls. The authors concluded that merged segments and exaggerated S3 may represent esophageal hypercontractility disorder from abnormal relaxation and/or contraction, and the Chicago classification for these contraction patterns may not be sensitive.
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