Amyl nitrate inhalation test is used to detect
High-Yield Explanation
Amyl nitrate inhalation (useful adjunct to the radiographic examination)seems to distinguish patients with pseudoachalasia from those with idiopathic achalasia. *In pseudoachalasia patients with tumour infiltration of the distal oesophagus, the narrow lower oesophagal sphincter segment was unaffected by the smooth-muscle relaxant effect of amyl nitrite. *amyl nitrate caused a measurable increase of 2 mm or more in sphincter diameter in patients with idiopathic achalasia ( smooth-muscle relaxant effect of amyl nitrite).