Introduction Non-cardiac chest pain can present a clinical challenge to the gastroenterologist. Many causes remain undiagnosed and untreated.

Oesophageal spasm is frequently considered a cause of non-cardiac chest pain, but current diagnostic tools are often poor at making this diagnosis. High resolution oesophageal manometry is now the gold standard oesophageal motility test, and is a swallow-based assessment. Unfortunately most episodes of chest pain in this context are not swallow-related, and are usually sporadic and unpredictable. Thus most manometry assessments occur in the absence of a symptom event.

We propose that prolonged, ambulatory high resolution may be a tool that can detect these sporadic chest pain events and allow correlation to symptom episodes.

We aimed to test the diagnostic yield of a novel, ambulatory high resolution oesophageal manometry device in the diagnosis of non-cardiac chest pain.

Methods We studied 17 patients (7 male, 10 female, age range 14 to 66) with chest pain. All had cardiac pain excluded by cardiology review, and all had been studied with normal upper GI endoscopy. All had also had major oesophageal motor disorder (including spasm) excluded by swallow-based high resolution manometry (with liquid and solid swallows).

An ultra-thin high resolution solid-state catheter was inserted transnasally into the oesophagus. This was connected to a small laptop and battery pack carried in a backpack. Patients were sent home and encouraged to mobilise. Patients were asked to keep the catheter in place at least until a symptomatic pain event was perceived. Symptom events were self-marked on a recorder device that was subsequently synchronised with the manometry output. Manometry tracings were read manually, and motor events at the time of symptoms were examined in detail.

Results The median duration of recording with the system was 12 hours, 13 minutes (range 5 hours, 30 minutes to 26 hours, 40 minutes).

12 of the 17 patients perceived typical chest pain symptom during recording.

Of the 12 with typical symptoms, 3 (25%) had clinically important findings that changed management. They had significant oesophageal spasm, pressurisation and shortening associated with pain events. These have been treated successfully with oesophageal body Botox injections (2 patients) and with long laparoscopic myotomy (1 patient). The remaining 9 patients either had no abnormalities, or minor abnormalities that did not correspond to symptoms.

Conclusion Ambulatory high-resolution manometry is a novel tool for investigation of non-cardiac chest pain. In our series, we identified management-altering abnormalities in 3 of 17 patients who had previously been investigated with normal cardiac, endoscopic and stationary manometric evaluation.

Disclosure of Interest J. Ooi: None Declared, E. Yazaki: None Declared, K. Nikaki: None Declared, D. Sifrim Grant/research support from: Research grant from Sandhill Scientific, P. Woodland: None Declared