 Three other criteria for definition of the nutcracker esophagus have been defined.The Gothenburg criterion consists of the presence of peristaltic contractions, with an amplitude of 180 mm Hg at any place in the esophagus.The Richter criterion involves the presence of peristaltic contractions with an amplitude of greater than 180 mm Hg from an average of measurements taken 3 and 8 cm above the lower esophageal sphincter.