Figure 3 Correlation matrix for the 4 phenotypes of symptomatic reflux. Some parameters were negatively related, represented in blue, and others were positively related, represented in red. The darker the color, the higher the correlation was. P – phenotype; T – total; U – upright; R – recumbent; SS – single swallow; MRS – multiple rapid swallows; DL – distal latency; DCI – distal contractile integral; CFV – contractile front velocity; IRP – integrated relaxation pressure; LESP – lower esophageal sphincter pressure; MNBI – mean nocturnal baseline impedance; AET – acid exposure percent time; BET – bolus exposure percent time; BCT – bolus clearance time.