Background & aims: Intraluminal pressure recording systems have not demonstrated predictable esophageal motor correlates of unexplained chest pain. This study used continuous high-frequency intraluminal ultrasonography to characterize esophageal contraction at the time of spontaneous and provoked chest pain.
Methods: Intraluminal pressure, pH, and ultrasound images of the esophagus were recorded for a maximum of 24 hours in 10 subjects with unexplained chest pain. Changes in esophageal muscle thickness were measured as a marker of muscle contraction. Ten additional subjects with suspected esophageal chest pain were studied after edrophonium chloride injection to provoke symptoms. Ten healthy subjects were studied as controls.
Results: Eighteen of 24 spontaneous chest pain episodes were preceded by a sustained esophageal contraction (SEC) detected on ultrasonography (mean duration, 68.0 seconds). This motor pattern was not accompanied by changes in intraluminal pressure. Four of 24 asymptomatic control periods were accompanied by SEC, although these contractions were of shorter mean duration (29.0 seconds; P < 0.001). SEC was observed in 5 subjects with a positive chest pain response to edrophonium and in none of the 5 subjects with a negative response. SEC was not detected in normal subjects.
Conclusions: There is a strong temporal correlation between a previously unrecognized esophageal motor event, SEC, and both spontaneous and provoked esophageal chest pain.