N. De Bortoli

Esophageal baseline impedance levels in patients with pathophysiological characteristics of functional heartburn.

Recently, it has been suggested that low esophageal basal impedance may reflect impaired mucosal integrity and increased acid sensitivity. We aimed to compare baseline impedance levels in patients with heartburn and pathophysiological characteristics related to functional heartburn (FH) divided into two groups on the basis of symptom relief after proton pump inhibitors (PPIs).

Proton pump inhibitor responders who are not confirmed as GERD patients with impedance and pH monitoring: who are they?

A short‐course of proton pump inhibitors (PPIs) is often used to confirm gastroesophageal reflux disease (GERD). However, some patients with PPI responsive heartburn do not seem to have evidence of GERD on impedance‐pH monitoring (MII‐pH). The aim of the study was to evaluate patients with reflux symptoms and a negative endoscopy, who well respond to PPIs with MII‐pH.

Esophagogastric junction morphology is associated with a positive impedance-pH monitoring in patients with GERD

High‐resolution manometry (HRM) provides information on esophagogastric junction (EGJ) morphology, distinguishing three different subtypes. Data on the correlation between EGJ subtypes and impedance‐pH detected reflux patterns are lacking. We aimed to correlate the EGJ subtypes with impedance‐pH findings in patients with reflux symptoms.

Esophagogastric junction contractility for clinical assessment in patients with GERD: a real added value?

The role of esophagogastric junction contractile integral (EGJ‐CI) as assessed by high‐resolution manometry (HRM) is unclear. We aimed to correlate the EGJ‐CI with impedance‐pH findings in gastro‐esophageal reflux disease (GERD) patients.

Reflux pattern and role of impedance-pH variables in predicting PPI response in patients with suspected GERD-related chronic cough.

Gastro‐oesophageal reflux disease (GERD) may contribute to the onset of chronic cough (CC); however, the multichannel intraluminal impedance‐pH (MII‐pH) monitoring is often within the normal range and the response to proton pump inhibitors (PPIs) unsatisfactory. The measure of impedance baseline (IB) increases the sensitivity of MII‐pH in patients with typical symptoms.

The added diagnostic value of postreflux swallow-induced peristaltic wave index and nocturnal baseline impedance in refractory reflux disease studied with on-therapy impedance-pH monitoring

On‐therapy impedance‐pH monitoring in proton pump inhibitor (PPI)‐refractory gastroesophageal reflux disease (GERD) yielded conflicting results. We aimed to assess the diagnostic value of postreflux swallow‐induced peristaltic wave (PSPW) index and mean nocturnal baseline impedance (MNBI) in PPI‐refractory heartburn.

Vigor of peristalsis during multiple rapid swallows is inversely correlated with acid exposure time in patients with NERD

Multiple rapid swallowing (MRS) during high‐resolution manometry (HRM) is increasingly utilized as provocative test to assess esophageal peristaltic reserve. The aim of this study was to evaluate the correlation between MRS response and impedance and pH (MII‐pH) parameters in endoscopy negative heartburn (ENH) patients.

The natural history of gastro-esophageal reflux disease: a comprehensive review.

Gastroesophageal reflux disease (GERD) is a common disorder of the upper gastrointestinal tract which is typically characterized by heartburn and acid regurgitation. These symptoms are widespread in the community and range from 2.5% to more than 25%. Economic analyses showed an increase in direct and indirect costs related to the diagnosis, treatment and surveillance of GERD and its complications. The aim of this review is to provide current information regarding the natural history of GERD, taking into account the evolution of its definition and the worldwide gradual change of its epidemiology. Present knowledge shows that there are two main forms of GERD, that is erosive reflux disease (ERD) and non-erosive reflux disease (NERD) and the latter comprises the majority of patients (up to 70%). The major complication of GERD is the development of Barrett esophagus, which is considered as a pre-cancerous lesion. Although data from medical literature on the natural history of this disease are limited and mainly retrospective, they seem to indicate that both NERD and mild esophagitis tend to remain as such with time and the progression from NERD to ERD, from mild to severe ERD and from ERD to Barretts esophagus may occur in a small proportion of patients, ranging from 0 to 30%, 10 to 22% and 1 to 13% of cases, respectively. It is necessary to stress that these data are strongly influenced by the use of powerful antisecretory drugs (PPIs). Further studies are needed to better elucidate this matter and overcome the present limitations represented by the lack of large prospective longitudinal investigations, absence of homogeneous definitions of the various forms of GERD, influence of different treatments, clear exclusion of patients with functional disorders of the esophagus.

Randomised clinical trial: twice daily esomeprazole 40 mg vs. pantoprazole 40 mg in Barrett's oesophagus for 1 year

Aliment Pharmacol Ther 2011; 33: 1019–1027

Lower pH values of weakly acidic refluxes as determinants of heartburn perception in gastroesophageal reflux disease patients with normal esophageal acid exposure

Multichannel impedance pH monitoring has shown that weakly acidic refluxes are able to generate heartburn. However, data on the role of different pH values, ranging between 4 and 7, in the generation of them are lacking. The aim of this study was to evaluate whether different pH values of weakly acidic refluxes play a differential role in provoking reflux symptoms in endoscopy-negative patients with physiological esophageal acid exposure time and positive symptom index and symptom association probability for weakly acidic refluxes. One hundred and forty-three consecutive patients with gastroesophageal reflux disease, nonresponders to proton pump inhibitors (PPIs), were allowed a washout from PPIs before undergoing: upper endoscopy, esophageal manometry, and multichannel impedance pH monitoring. In patients with both symptom index and symptom association probability positive for weakly acidic reflux, each weakly acidic reflux was evaluated considering exact pH value, extension, physical characteristics, and correlation with heartburn. Forty-five patients with normal acid exposure time and positive symptom association probability for weakly acidic reflux were identified. The number of refluxes not heartburn related was higher than those heartburn related. In all distal and proximal liquid refluxes, as well as in distal mixed refluxes, the mean pH value of reflux events associated with heartburn was significantly lower than that not associated. This condition was not confirmed for proximal mixed refluxes. Overall, a low pH of weakly acidic reflux represents a determinant factor in provoking heartburn. This observation contributes to better understand the pathophysiology of symptoms generated by weakly acidic refluxes, paving the way toward the search for different therapeutic approaches to this peculiar condition of esophageal hypersensitivity.