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Is peristalsis always normal ?
R. W. McCallum (Charlottesville)
I will first review comparison of contraction amplitudes at 5 and 10 cm above the LES in a series of 30 normal volunteers and in patients who were symptomatic for the spectrum of non-cardiac chest pain and, by manometric criteria, qualified for the diagnosis of high amplitude (nutcracker esophagus) [1]. Adopting a standard of mean plus deviations, we concluded that a mean amplitude of 180 mm Hg was present in the high amplitude peristaltic patients compared to 85 mm Hg for the normal subjects when measuring amplitude 5 cm above the LES (figure 1 - A and B).
Figure 1 A. Schematic representation of esophageal motor function. The lower esophageal sphincter relaxes at the onset of swallowing. A propagated contraction is shown from the proximal esophagus through the lower esophageal sphincter.
Figure 1 B. Esophageal contraction amplitudes at 5 and 10 cm above the LES in normal subjects (n = 30) and in patients with HAPC (n = 20). Normals and patients differ significantly at both sites. For each group the values at 5 and 10 cm differ significantly.
I will now review the peristaltic wave form. Normal subjects have a very small percentage of bi-peaked waves; approximately 5 p. cent at 5 cm above the LES and negligible at 10 cm above the LES. Whereas patients with the high amplitude peristaltic contractions have significantly more bi and tri-peaked waves, some ranging up to 50-70 p. cent of their contractions were bi-peaked at 5 and 10cm (figure 2). In addition, both amplitude and duration increase distally in the esophagus. The percent of the amplitude increase is greater than the percent of the duration increase. The amplitude abnormality is much more impressive. These percent increases in both amplitude and duration are greater than those seen in
Figure 2. Percent bipeaked waves at 5 and 10 cm above the LES in normal subjects (n = 30) and in patients with HAPC (n = 20). Normals and patients differ significantly at both sites. For each group the values at 5 and 10 cm differ significantly.
normal subjects (figure 3). Abnormal amplitude is not limited to the distal 5 cm above the LES but occurs also at 10 cm. Abnormal duration is also present at both 5 and 10 cm, greater than 7 seconds being considered criteria for abnormal.
I will now review peristalsis in healthy volunteers versus the patients with suspected nutcracker esophagus. In normals, when a mean and 2 or 3 standard deviations were calculated, at least 75 p. cent of contractions were persitaltic. Invariably, nutcracker esophagus patients met this qualification, and thus had normal peristaltic frequency. In addition, nutcracker esophagus patients have normal resting intra-esophageal pressure.
Figure 3. Esophageal contraction durations at 5 and 10 cm above the LES in normal subjects (n = 30) and in patients with HAPC (n = 20). Normals and patients differ significantly at both sites. For each group the values at 5 and 10 cm differ significantly.
In summary, peristalsis in the entity of nutcracker esophagus is normal (defined as > 75 p. cent of contractions being peristaltic). We recommend evaluating 20 or more wet swallows of 5 cc boluses in order to document peristaltic function during a clinical esophageal motility study [1].
Reference
I. Traube M, McCallum RW (1987) Comparison of esophageal manometric characteristics in asymptomatic subjects and symptomatic patients with high-amplitude esophageal peristaltic contractions. Am J Gastroenterology 82 (9): 831-835.
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