Computing the distal contractile integral (DCI) using esophageal pressure topography

The DCI is the measure of the vigor of the distal esophageal contraction utilized in the Chicago Classification. As such it is measured between the proximal and distal pressure troughs for the duration of contraction within this region. To exclude vascular artifacts and intrabolus pressures from the measurement, only pressures greater than 20 mmHg are considered. Hence, the sum of all pressures within the white dotted rectangle in the figure equals the DCI; the units of measurement for the DCI are mmHg-s-cm.