Distal esophageal spasm in high-resolution esophageal pressure topography: defining clinical phenotypes

Abstract

Background: The manometric diagnosis of distal esophageal spasm (DES) uses "simultaneous contractions" as a defining criterion, ignoring the concept of short latency distal contractions as an important feature. Our aim was to apply standardized metrics of contraction velocity and latency to high-resolution esophageal pressure topography (EPT) studies to refine the diagnosis of DES.

Methods: Two thousand consecutive EPT studies were analyzed for contractile front velocity (CFV) and distal latency to identify patients potentially having DES. Normal limits for CFV and distal latency were established from 75 control subjects. Clinical data of patients with reduced distal latency and/or rapid CFV were reviewed.

Results: Of 1070 evaluable patients, 91 (8.5%) had a high CFV and/or low distal latency. Patients with only rapid contractions (n = 186 [17.4%] using conventional manometry criteria; n = 85 [7.9%] using EPT criteria) were heterogeneous in diagnosis and symptoms, with the majority ultimately categorized as weak peristalsis or normal. In contrast, 96% of patients with premature contraction had dysphagia, and all (n = 24; 2.2% overall) were ultimately managed as spastic achalasia or DES.

Conclusions: The current DES diagnostic paradigm focused on "simultaneous contractions" identifies a large heterogeneous set of patients, most of whom do not have a clinical syndrome suggestive of esophageal spasm. Incorporating distal latency into the diagnostic algorithm of EPT studies improves upon this by isolating disorders of homogeneous pathophysiology: DES with short latency and spastic achalasia. We hypothesize that prioritizing measurement of distal latency will refine the management of these disorders, recognizing that outcomes trials are necessary.

Figure 1

The concept of reduced distal latency in spasm as described by Behar and Biancani. (A) The latency of propagation for normal controls (blue circles) and a patient with spasm (white circles) adapted from Behar and Biancani. The latency interval was measured using conventional manometry as time from onset of contraction at sensor 21 to onset of contraction at sensor 1. The latency interval was determined to be a marker of the inhibitory ganglionic integrity, suggesting that patients with spasm had evidence of reduced latency and premature contraction. In the right panels, the latency interval plots from the conventional manometry study are superimposed on EPT tracings of a swallow with normal latency (top) and short latency (bottom). In each case, the time and sensor position scales are adjusted to approximate those of the conventional manometry tracing.

Figure 2

Measurement of DL and CFV in an EPT plot of a normal swallow. The black line is the 30-mm Hg isobaric contour circumscribing areas on the plot with intraluminal pressure >30 mm Hg. The peristaltic esophageal contraction has 2 pressure troughs, 1 centered proximally at P and 1 distally at D. The CDP represents the inflexion point in the contractile front propagation. It is localized by fitting 2 tangential lines to the initial and terminal portions of the 30-mm Hg isobaric contours and noting intersection of the lines (white dot). The CFV is calculated by taking the best-fit tangent of the 30-mm Hg isobaric contour between P and CDP. The distal latency is measured from UES relaxation to the CDP.

Figure 3

EPT phenotypes of abnormal propagation based on DL and CFV measurements. The most common phenotypes were A and B with normal latency and a large defect in the 30-mm Hg isobaric contour. The swallow in (A) with a rapid contraction and a large proximal break fulfills criteria for both weak peristalsis and rapid contraction. (B) Illustrates the problem with measuring CFV with weak peristalsis and a nonpropagating segmental contraction. Although the CDP provides a reasonable temporal end point for measuring velocity, the large break eliminates any appropriate proximal landmark resulting in what would be a negative CFV. However, the DL is normal suggesting this to be an artifact of weak peristalsis. The swallow in (C) is also associated with a large break (7.5 cm); however, it is also associated with short latency (3.0 s) and rapid CFV (45 cm/s), thereby representing a distinct phenotype compared to (A) and (B). The swallow in (D) is premature (DL = 4.4 s) with a normal CFV (6 cm/s). This swallow is associated with impaired EGJ relaxation and bolus pressurization consistent with functional EGJ obstruction or an achalasia variant.

Figure 4

Blinded diagnoses of 91 EPT studies with rapid propagation subdivided into studies with short distal latency (<4.5 s) or rapid CFV. Patients with premature contractions defined by a distal latency <4.5 seconds were uniformly diagnosed with a spastic disorder of the distal esophagus. In contrast, patients with only a rapid CFV were likely to have a non-spastic disorder, especially weak peristalsis.