BACKGROUND: Differentiating acute chest pain caused by myocardial ischaemia from 
other, potentially more benign causes of chest pain is a frequent diagnostic 
challenge faced by Emergency Department (ED) clinicians. Only 30% of patients 
presenting with chest pain will have a cardiac origin for the pain, and 
gastro-oesophageal disorders are one of the common sources of non-cardiac chest 
pain, yet remain clinically difficult to differentiate from cardiac pain.
AIM: A systematic review of the literature was conducted to locate and evaluate 
clinical trials comparing the use of an oral gastrointestinal (GI) cocktail 
(oral viscous lidocaine/ antacid ± anticholinergic) to standard diagnostic 
protocols (serial electrocardiograms (ECGs), serial biomarkers, imaging and/ or 
provocative testing) to differentiate emergency patients presenting with acute 
chest pain caused by gastro-oesophageal disease from those with other 
aetiologies.
METHODS: Studies were identified by searching electronic databases, scanning 
reference lists of articles, and searching clinical trial databases for 
relevantly currently registered trials. The search included PubMed (1966 - 
present), Embase (1980 - present) and Cochrane Central Register of Controlled 
Trials (CENTRAL). The identified studies were evaluated with a modified QUADAS 
tool.
RESULTS: A total of four studies were identified for inclusion in the review. 
Studies were of low methodological quality with heterogeneous results. There 
were no adequately powered and appropriately designed studies identified.
DISCUSSION: Current diagnostic protocols for Acute Coronary Syndrome (ACS) 
revolve around early and serial ECG monitoring and cardiac biomarker testing, 
imaging and careful clinical examination. In patients with chest pain and 
suspected ACS, the use of a GI cocktail compared with standard diagnostic 
protocols (serial ECG and biomarkers and provocative testing or imaging) is not 
proven to improve accuracy of diagnosis, and cannot reliably exclude myocardial 
ischaemia.