Esophageal perception and noncardiac chest pain

The Role of Psychological Factors in Noncardiac Chest Pain of Esophageal Origin

Background/Aims

Noncardiac chest pain (NCCP) of esophageal origin is a challenging clinical problem of diverse etiology that affects more than 80 million Americans yearly. We assess the prevalence and impact of psychological disorders on NCCP of esophageal origin, describe possible mechanisms associated with this condition, and review psychological therapy options.

Methods

Online search using PubMed and Medline from January 1, 1966, to April 30, 2023.

Results

Psychological disorders have been reported in up to 79% of patients with NCCP of esophageal origin. Several psychological disturbances have been identified with this condition, including depression, anxiety, panic disorder, phobias, and obsessive-compulsive and somatoform disorders. It is unclear whether the psychological disorders trigger the chest pain or vice versa. Multiple psychological mechanisms have been linked to chest pain and may contribute to its pathogenesis and severity. These mechanisms include cardiophobia, poor coping strategies, negative social problem solving, stress and perceived control, hypervigilance to cardiopulmonary sensations, altered pain perception, and alexithymia. Psychological therapies for NCCP of esophageal origin include cognitive behavioral therapy, hypnotherapy, physical and relaxation training, breathing retraining, and alternative medicine. Among the therapeutic options, cognitive behavioral therapy has been shown to be an effective treatment for NCCP of esophageal origin.

Conclusion

This review raises awareness about the high prevalence of psychological disorders in NCCP of esophageal origin and highlights the need for clinical trials and trained therapists to address the management of this taxing clinical problem.

The Real Relevance of Nonacid Reflux in Pediatric Patients

Gastroesophageal reflux (GER) is one of the most common presenting complaints to pediatric gastroenterologists, and a wide variety of symptoms in children are potentially attributable to typical or atypical GER. While reflux diagnosis and treatment paradigms classically have focused on targeting acid, there is a growing recognition of the prevalence and significance of nonacid GER in both children and adults. This review explores the role of nonacid reflux in pediatric patients, including definitions, associations with symptoms, pathophysiologic mechanisms, and treatment implications.

Acid-suppressive therapy with esomeprazole for relief of unexplained chest pain in primary care: a randomized, double-blind, placebo-controlled trial

OBJECTIVES

High-quality data regarding the efficacy of acid-suppressive treatment for unexplained chest pain are lacking. The aim of this study was to evaluate the efficacy of esomeprazole in primary-care treatment of patients with unexplained chest pain stratified for frequency of reflux/regurgitation symptoms.

METHODS

Patients with a ≥ 2-week history of unexplained chest pain (unrelated to gastroesophageal reflux) who had at least moderate pain on ≥ 2 of the last 7 days were stratified by heartburn/regurgitation frequency (≤ 1 day/week (stratum 1) vs. ≥ 2 days/week (stratum 2)) and randomized to 4 weeks of double-blind treatment with twice-daily esomeprazole 40 mg or placebo. Chest pain relief during the last 7 days of treatment (≤ 1 day with minimal symptoms assessed daily using a 7-point scale) was analyzed by stratum in keeping with the predetermined analysis plan.

RESULTS

Overall, 599 patients (esomeprazole: 297, placebo: 302) were randomized. In stratum 1, more esomeprazole than placebo recipients achieved chest pain relief (38.7% vs. 25.5%; P=0.018); no between-treatment difference was observed in stratum 2 (27.2% vs. 24.2%; P=0.54). However, esomeprazole was superior to placebo in a post-hoc analysis of the whole study population (combined strata; 33.1% vs. 24.9%; P=0.035).

CONCLUSIONS

A 4-week course of high-dose esomeprazole provided statistically significant relief of unexplained chest pain in primary-care patients who experienced infrequent or no heartburn/regurgitation, but there was no such significant reduction in patients with more frequent reflux symptoms.

Noncardiac chest pain: gastroesophageal reflux disease

Noncardiac chest pain (NCCP) is not only a difficult disorder to define but is also complex in characterization and treatment. Patients with NCCP are a challenge to primary care and subspecialty services such as cardiology and gastroenterology. NCCP is often a heterogeneous disorder with many potential causes including gastroenterologic diagnoses. This article presents the current evidence for gastroesophageal reflux disease as a cause of NCCP and highlights the best currently available tests for this group of patients.

Intraesophageal chemicals enhance responsiveness of upper thoracic spinal neurons to mechanical stimulation of esophagus in rats

Esophageal hypersensitivity is one of the most common causes of noncardiac chest pain in patients. In this study, we investigated whether exposure of the esophagus to acid and other chemical irritants affected activity of thoracic spinal neurons responding to esophageal distension (ED) in rats. Extracellular potentials of single thoracic (T3) spinal neurons were recorded in pentobarbital sodium-anesthetized, -paralyzed, and -ventilated male rats. ED (0.2 or 0.4 ml, 20 s) was produced by water inflation of a latex balloon placed orally into the middle thoracic region of the esophagus. The chemicals were administered via a tube that was passed through the stomach and placed in the thoracic esophagus. To irritate the esophagus, 0.2 ml of HCl (0.01 N), bradykinin (10 microg/ml), or capsaicin (10 microg/ml) were injected for 1-2 min. Only neurons excited by ED were included in this study. Results showed that intraesophageal instillation of HCl, bradykinin, and capsaicin increased activity in 3/20 (15%), 7/25 (28%), and 9/20 (45%) neurons but enhanced excitatory responses to ED in 9/17 (53%), 8/15 (53%), and 7/11 (64%) of the remaining spinal neurons, respectively. Furthermore, intraesophageal chemicals were more likely to enhance the responsiveness of low-threshold neurons than high-threshold neurons to the esophageal mechanical stimulus. Normal saline (pH 7.4, 0.2 ml) or vehicle instilled in the esophagus did not significantly affect activity or ED responses of neurons. We conclude that enhanced responses of thoracic spinal neurons to ED by the chemically challenged esophagus may provide a possible pathophysiological basis for visceral hypersensitivity in patients with gastroesophageal reflux and/or esophagitis.

Electrophysiological characterization of vagal afferents relevant to mucosal nociception in the rat upper oesophagus

Emerging evidence indicates a nociceptive role of vagal afferents. A distinct oesophageal innervation in the rat, with muscular and mucosal afferents travelling predominantly in the recurrent (RLN) and superior laryngeal nerve (SLN), respectively, enabled characterization of mucosal afferents with nociceptive properties, using novel isolated oesophagus-nerve preparations. SLN and RLN single-fibre recordings identified 55 and 14 units, respectively, with none conducting faster than 8.7 m s(-1). Mucosal response characteristics in the SLN distinguished mechanosensors (n = 13), mechanosensors with heat sensitivity (18) from those with cold sensitivity (19) and a mechanoinsensitive group (5). The mechanosensitive fibres, all slowly adapting, showed a unimodal distribution of mechanical thresholds (1.4-128 mN, peak approximately 5.7 mN). No difference in response characteristics of C and Adelta fibres was encountered. Mucosal proton stimulation (pH 5.4 for 3 min), mimicking gastro-oesophageal reflux disease (GORD), revealed in 31% of units a desensitizing response that peaked around 20 s and faded within 60 s. Cold stimulation (15 degrees C) was proportionally encoded but the response showed slow adaptation. In contrast, the noxious heat (48 degrees C) response showed no obvious adaptation with discharge rates reflecting the temperature's time course. Polymodal (69%) mucosal units, > 30% proton sensitive, were found in each fibre category and were considered nociceptors; they are tentatively attributed to vagal nerve endings type I, IV and V, previously morphologically described. All receptive fields were mapped and the distribution indicates that the posterior upper oesophagus may serve as a 'cutbank', detecting noxious matters, ingested or regurgitated, and triggering nocifensive reflexes such as bronchoconstriction in GORD.

Role of clinical presentation in diagnosing reflux-related non-cardiac chest pain

INTRODUCTION

Non-cardiac chest pain (NCCP) presents as a frequent diagnostic challenge, with patients tending to use a disproportionate level of health-care resources. Gastroesophageal reflux disease (GERD) is the most frequent cause of NCCP. Thus the typical symptoms of reflux, such as heartburn and regurgitation, when present as predominant symptoms are quite specific for diagnosing GERD but in patients with NCCP the clinical diagnosis of reflux is difficult, and invasive methods or the omeprazole test are required for its detection. The aim of the present study was to evaluate the role of clinical presentation when diagnosing GERD among patients with NCCP.

METHODS

Patients with NCCP underwent upper endoscopy, Bernstein and omeprazole tests. The patients were divided into two groups based on GER- or non-GER-related chest pain, and clinical presentation was compared between these two groups. Gastroesophageal reflux disease was considered positive when at least two methods were positive.

RESULTS

From 78 NCCP patients (41 male; mean age 50.4 +/- 2.3 years), the chest pain was related to GERD in 35 patients (44.8%). The two groups were the same based on sex and age. The chest pain severity, site, radiation and relation to food, exercise, and sleep were equal in the two groups, except for two symptoms: pain that was relieved by antacid (P < 0.031) and presence of classical reflux symptoms (P < 0.009), seen in the GERD patients. With regard to recent patient history, heartburn and regurgitation symptoms were seen more frequently in GERD patients (P < 0.036 and P < 0.002, respectively).

DISCUSSION

Clinical presentation is important in diagnosing GERD in NCCP. Although the chest pain is the same in reflux- and non-reflux-related NCCP, the symptoms of heartburn or regurgitation in the present or recent patient history are diagnostic for GERD-related chest pain.

Innervation of the mammalian esophagus

Understanding the innervation of the esophagus is a prerequisite for successful treatment of a variety of disorders, e.g., dysphagia, achalasia, gastroesophageal reflux disease (GERD) and non-cardiac chest pain. Although, at first glance, functions of the esophagus are relatively simple, their neuronal control is considerably complex. Vagal motor neurons of the nucleus ambiguus and preganglionic neurons of the dorsal motor nucleus innervate striated and smooth muscle, respectively. Myenteric neurons represent the interface between the dorsal motor nucleus and smooth muscle but they are also involved in striated muscle innervation. Intraganglionic laminar endings (IGLEs) represent mechanosensory vagal afferent terminals. They also establish intricate connections with enteric neurons. Afferent information is implemented by the swallowing central pattern generator in the brainstem, which generates and coordinates deglutitive activity in both striated and smooth esophageal muscle and orchestrates esophageal sphincters as well as gastric adaptive relaxation. Disturbed excitation/inhibition balance in the lower esophageal sphincter results in motility disorders, e.g., achalasia and GERD. Loss of mechanosensory afferents disrupts adaptation of deglutitive motor programs to bolus variables, eventually leading to megaesophagus. Both spinal and vagal afferents appear to contribute to painful sensations, e.g., non-cardiac chest pain. Extrinsic and intrinsic neurons may be involved in intramural reflexes using acetylcholine, nitric oxide, substance P, CGRP and glutamate as main transmitters. In addition, other molecules, e.g., ATP, GABA and probably also inflammatory cytokines, may modulate these neuronal functions.

The heart and the oesophagus: intimate relations

The close anatomical relations of the heart and oesophagus, and the similarity of symptoms attributable to disorders of either organ, often lead to diagnostic difficulty in patients with chest pain. A definitive diagnosis of non-cardiac chest pain attributable to oesophageal reflux or spasm is hampered, both by the need for prolonged ambulatory monitoring of pH, manometry, and endoscopy, and by the common occurrence of asymptomatic reflux and spasm, and the corresponding difficulty in linking an episode of reflux or spasm with an episode of pain. Moreover, some patients with non-cardiac chest pain and normal tests of oesophageal structure and function have centrally mediated hypersensitivity, both within and without the oesophagus. Rather than proceed with investigations, in the absence of symptoms to suggest structural disease of the oesophagus, it would be reasonable to attempt symptomatic treatment with a proton pump inhibitor or an antidepressant.

The pathophysiology of non-cardiac chest pain

Various underlying mechanisms have been described in patients with non-cardiac chest pain (NCCP). By far, gastroesophageal reflux disease (GERD) is the most common cause and thus requires initial attention when patients with NCCP are managed. Esophageal dysmotility can be demonstrated in 30% of the NCCP patients, but appears to play a very limited role in symptom generation. A significant number of patients with NCCP lack any evidence of GERD and have been consistently shown to have reduced perception thresholds for pain. Peripheral and/or central sensitization have been suggested to be responsible for visceral hypersensivity in NCCP patients. Further understanding of the underlying mechanisms for pain in patients with NCCP will likely improve our current therapeutic approach.

Performance, tolerability, and symptoms related to prolonged pH monitoring using the Bravo system in Mexico

BACKGROUND

The traditional system for esophageal 24-h pH monitoring requires transnasal introduction of the catheter with pH sensors; this technique produces discomfort, inconvenience, and interference with daily activity. Recently, a catheter-free pH monitoring system (Bravo) has been proposed as an alternative and promising method for 24-h pH.

AIM

To evaluate performance, tolerability, and symptoms related to this new technology in our population.

METHODS

Consecutive patients with gastroesophageal reflux disease (GERD) with indication for 24-h pH were included. pH Bravo capsule was placed 6 cm above the squamocolumnar junction using endoscopic measurement. Symptoms associated were evaluated daily in a personal diary until 7 days after the capsule attachment. Severity of symptoms was assessed by a 5-point Likert scale. Capsule detachment was assessed by chest X-ray.

RESULTS

Eighty-four patients were included. Forty-nine were female (mean age 44 +/- 12 yr). Indications for pH monitoring were: nonresponse to proton pump inhibitor therapy in 38 (45%), preoperative evaluation for anti-reflux surgery in 36 (43%), previous failed transnasal 24-h pH monitoring in 6 (7%), and extra-esophageal manifestations of GERD in 4 (5%). The capsule was successfully attached in 95% of patients. At day 7, capsule detachment occurred spontaneously in all cases. Symptoms related to capsule attachment were: chest pain in 26 (33%), foreign body sensation in 11 (14%), nausea in 5 (6%), and 9 (11%) patients had more than one symptom. Severities of those symptoms were mild, and no patient required removal of the capsule. Women and younger patients had more symptoms related to the procedure (p < 0.05).

CONCLUSIONS

Esophageal pH monitoring with Bravo capsule is a safe, reliable, and tolerable method in patients with GERD.