Erroneous Diagnosis of Gastroesophageal Reflux Disease in Achalasia Boudewijn F. Kessing, Albert J. Bredenoord, André J.P.M. Smout  Clinical Gastroenterology and Hepatology  Volume 9, Issue 12, Pages 1020-1024 (December 2011) DOI: 10.1016/j.cgh.2011.04.022 Copyright © 2011 AGA Institute Terms and Conditions

Figure 1 Fragment of 24-hour pH measurement in a patient with achalasia. Stasis of food with acidic contents is responsible for a long episode with pH <4. Clinical Gastroenterology and Hepatology 2011 9, 1020-1024DOI: (10.1016/j.cgh.2011.04.022) Copyright © 2011 AGA Institute Terms and Conditions

Figure 2 Impedance tracing measured in a normal subject and an achalasia patient. The impedance tracings in the achalasia patients are characterized by low distal baseline impedance levels. Clinical Gastroenterology and Hepatology 2011 9, 1020-1024DOI: (10.1016/j.cgh.2011.04.022) Copyright © 2011 AGA Institute Terms and Conditions

Figure 3 Classic achalasia, which is identified by absent LES relaxation and absent peristalsis as measured by conventional manometry. Clinical Gastroenterology and Hepatology 2011 9, 1020-1024DOI: (10.1016/j.cgh.2011.04.022) Copyright © 2011 AGA Institute Terms and Conditions

Figure 4 High-resolution manometry plot of classic achalasia, which is identified by the absence of LES relaxation and no peristaltic contractions of the esophagus after the onset of a swallow. Clinical Gastroenterology and Hepatology 2011 9, 1020-1024DOI: (10.1016/j.cgh.2011.04.022) Copyright © 2011 AGA Institute Terms and Conditions