WHAT IS THE OPTIMAL TIME WINDOW IN SYMPTOM ANALYSIS OF 24-HOUR ESOPHAGEAL PRESSURE AND PH DATA

Since noncardiac chest pain is the only well-established indication fo r 24-hr esophageal pH and pressure recording, the analysis of the asso ciation between chest pain episodes and esophageal motility abnormalit ies or reflux is the most important part of data analysis in 24-hr mon itoring. Until now, different time windows have arbitrarily been used by various research groups. The aim of this study was to determine the optimal time window for symptom analysis in 24-hr esophageal pH and p ressure monitoring. For this purpose repetitive symptom association an alysis was carried out, using time windows of various onsets and durat ions. For each time window, the symptom indices for reflux and dysmoti lity were calculated. The symptom index for both reflux and dysmotilit y showed a gradual increase for windows with increasingly early onset, following a pattern that would be predicted on the basis of Poisson's theory. However, both indices had a relatively sharp cutoff point at 2 min before the onset of pain. Both indices only showed a predictable gradual increase when the time window starting at -2 min was extended beyond the moment of pain onset. It is concluded that the optimal tim e window for symptom analysis in 24-hr esophageal pH and pressure reco rding begins at 2 min before the onset of pain and ends at the onset o f pain.