Esophageal dysfunction in syndrome X.

Syndrome X is defined as anginal chest pain accompanied by objective signs of ischemia on exercise testing or myocardial scintigraphy, but with angiographically "normal" coronary arteries. The etiology of this enticing syndrome is still not known. Besides myocardial ischemia, esophageal dysfunction and visceral hypersensitivity may play a role in the development of pain. The purpose of this study was to study esophageal function and visceral sensitivity in patients with syndrome X. Twenty consecutive patients with the diagnosis of syndrome X were investigated with esophageal manometry and a 24-hour pH recording. Visceral esophageal sensitivity was explored by balloon distention of the distal esophagus, as well as by instillation of acid. Twelve patients (67% of the 18 evaluated) had some abnormality on 24-hour pH monitoring; 2 had abnormal global acid exposure time (pH <4) and 7 had symptoms coincidental with episodes of pH <4. Seven patients (35%) had esophageal dysmotility including 5 with the "nutcracker" esophagus. Esophageal hypersensitivity to acid (n = 9) or distention (n = 13) was seen in 14 of the 20 patients. Eleven patients received acid suppressive therapy that resulted in amelioration of chest pain in 8 (73%). Thus, results suggest that esophageal hypersensitivity rather than gross functional abnormality is an important factor for the development of chest pain in patients with syndrome X, and that acid in the context of a hypersensitive esophagus is the main culprit. Acid suppression may ameliorate pain in a substantial proportion of patients.