Input the pressure components identified in HRM to visualize the cumulative contractile vigor index.
Guidelines & Evidence
Clinical Details
Section 1
When to Use
When to Use
Standardized measurement of esophageal peristaltic vigor during High-Resolution Manometry (HRM)
To identify hypercontractile (Spastic) vs. hypocontractile (Ineffective) disorders
Fundamental component of the Chicago Classification (v3.0 and v4.0) diagnostic algorithm
Calculation logic
DCI is calculated for individual swallows using the "isobaric contour" tool on a manometry workstation. It integrates the pressure, duration, and length of the peristaltic contraction in the distal esophagus (from the transition zone to the proximal margin of the EGJ).
Pressure readings below 20 mmHg are "filtered out" to remove baseline variations, and readings within the Upper Esophageal Sphincter (UES) or Lower Esophageal Sphincter (LES) zones are excluded from the DCI calculation.
Section 3
Pearls/Pitfalls
Hypercontractility (Jackhammer)
A single hypercontractile swallow (DCI > 8000) does not make a diagnosis. The Chicago Classification v4.0 requires ≥ 20% of swallows to meet this threshold for a diagnosis of Jackhammer Esophagus.
Ineffective Motility (IEM)
The criteria for IEM changed in v4.0. It now requires > 70% ineffective swallows (DCI < 450) OR ≥ 50% failed swallows (DCI < 100). This higher bar reduces the over-diagnosis of IEM which is often a non-specific finding.
Clinical Pearls
DCI is the most reliable way to distinguish between mechanical obstruction and true muscular hypercontractility
Post-fundoplication dysphagia is often associated with a drop in DCI due to weak esophageal reserve
Opioids are a common cause of "manometric Jackhammer" (DCI > 8000) without primary smooth muscle pathology
Section 4
Next Steps
Diagnostic Integration
01
High DCI + High IRP: Screen for Type III Achalasia (Spastic).
02
High DCI + Normal IRP: Diagnosis of Jackhammer Esophagus.
03
Low DCI: Diagnosis of Ineffective Esophageal Motility (IEM).
Complementary Motility Tools
Chicago Classification v4.0 (HRM)
Integrated Relaxation Pressure (IRP) Calculator
Distal Latency (DL) Interpretation
Section 5
Evidence Appraisal
The Current Standard
The Chicago Classification version 4.0.
Yadlapati R et al. • Neurogastroenterology & Motility. 2021;33(1):e14058. Definitive reference for all HRM thresholds.
The concept of DCI was developed by the Chicago group to replace the "peak amplitude" measurement used in conventional manometry. It recognized that the "work" of the esophagus was better captured as a three-dimensional volume of pressure over time and distance.
