Differences in the Control of Secondary Peristalsis in the Human Esophagus: Influence of the 5-HT4 Receptor versus the TRPV1 Receptor

Response to multiple rapid swallows shows impaired inhibitory pathways in distal esophageal spasm patients with and without concomitant esophagogastric junction outflow obstruction

Distal esophageal spasm (DES) is a motility disorder characterized by premature contraction of the esophageal body during single swallows. It is thought to be due to impairment of esophageal inhibitory pathways, but studies to support this are limited. The normal response to multiple rapid swallows (MRS) is deglutitive inhibition of the esophageal body during the MRS sequence. Our aim was to compare the response to MRS in DES patients and healthy control subjects. Response to MRS during HRM was evaluated in 19 DES patients (8 with and 11 without concomitant esophagogastric junction outflow obstruction [EGJOO]) and 24 asymptomatic healthy controls. Patients with prior gastroesophageal surgery, peroral endoscopic myotomy, pneumatic dilation, esophageal botulinum toxin injection within 6 months of HRM, opioid medication use, and esophageal stricture were excluded. Response to MRS was evaluated for complete versus impaired inhibition (esophageal body contractility with distal contractile integral [DCI] > 100 mmHg-sec-cm during MRS), presence of post-MRS contraction augmentation (DCI post MRS greater than single swallow mean DCI), and integrated relaxation pressure (IRP). Impaired deglutitive inhibition during MRS was significantly more frequent in DES compared to controls (89% vs. 0%, P < 0.001), and frequency was similar for DES with versus without concomitant EGJOO (100% vs. 82%, P = 0.48). The proportion of subjects with augmentation post MRS was similar for both groups (37% vs. 38%, P = 1.00), but mean DCI post MRS was higher in DES than controls (3360.0 vs. 1238.9, P = 0.009). IRP was lower during MRS compared to single swallows in all patients, and IRP during MRS was normal in 5 of 8 patients with DES and EGJOO. Our study suggests that impaired deglutitive inhibition during MRS is present in the majority of patients with DES regardless of whether they have concomitant EGJOO, and future studies should explore the usefulness of incorporating response to MRS in the diagnosis of DES.