Jackhammer Esophagus: A Symptomatic Phenotype of Hypertensive Contraction in High Resolution Esophageal Pressure Topography (EPT)

Abstract

Background: Although hypertensive esophageal motor disorders have been linked to symptoms of chest pain and dysphagia, hypertensive peristalsis is heterogeneous, ranging from a normal variant to extreme degrees of hypercontractility. This study aimed to define an extreme phenotype of hypertensive peristalsis found in symptomatic patients that is not encountered in asymptomatic controls. Methods: A series of 2,000 consecutive clinical EPT studies performed from January 2007 until May 2010, all with consistent methodology (Sierra), were reviewed. After excluding patients with previous upper GI surgery, duplicate studies and technically-limited studies, we identified 30 subjects with ≥2 test swallows followed by a contraction with a DCI greater than 8,000 mmHg-cm-s (the maximal value observed in 72 controls). Because of their frequent repetitive vigorous morphology these contractions were branded the “jackhammer” pattern. Swallows exhibiting jackhammer contractions were then further analyzed for associated Integrated Relaxation Pressure (IRP), Contractile Front Velocity (CFV), Distal contractile Latency (DL), presence of repetitive contractions, and a novel metric describing the proportion of the distal segment concurrently contracting. The maximal Vertical Contraction (VC) length was calculated by exporting data files into MATLAB. A spatial pressure variation function of the greatest contractile pressure along the esophagus was calculated to identify the proximal (P) and the distal troughs (D). Using a fixed threshold of 30 mmHg, the contraction was search to find the instant characterized by maximal VC segment length between the P and D, expressed as a percentage of PD length and in cm. Results: Among the 30 patients, 4 had spastic achalasia and 1 DES. The 25 remaining patients (11 males, mean age 57 years, range 28-82) had jackhammer contractions with normal CFV and DL. Five of them had a mean IRP greater than 15 mmHg (range 15.7-51.2). Their main symptom was dysphagia in 19, chest pain in 2 and reflux in 4. The EPT findings of these subjects are described in the Table. Notably, only 9 patients of 25 fulfilled the criteria of spastic nutcracker as described in the Chicago Classification, circa 2009 [1] (mean DCI of all 10 swallows >8,000). Conclusion: We describe a phenotype of hypertensive contractions associated with multiple peaks and a longer vertical length of contraction (VC) compared to asymptomatic controls. These repetitive contractions evoke the action of jackhammer and we propose the name “jackhammer esophagus” to supplant the prior category “spastic nutcracker” which was not widely accepted. Jackhammer esophagus (2 peristaltic contractions with DCI >8,000) appears to be a physiologically homogeneous entity that is usually associated with dysphagia. [1] Pandolfino JE, et al. Neurogastroenterol Motil 2009;21:796.