The normal esophageal lead electrocardiogram

Abstract

The esophageal lead electrocardiogram has been analyzed in 40 normal subjects. As a rule, the records at ventricular levels closely resembled those from left chest leads. Near the atrioventricular groove (transition zone) and at atrial levels, an intrinsic deflection in the P wave, a deep broad Q, progressively smaller R and deeper S, and inverted T waves appeared. Immediately behind the atria, the P wave was of shorter duration, of greater complexity in configuration, and of greater voltage in all its components than elsewhere. T a (auricular repolarization) waves were frequently present in leads from this region. At these same levels, the ventricular complexes approached the configuration seen in Lead aV R, and at supra-atrial levels were almost identical. The P wave became inverted in the supra-atrial leads and resembled that seen in aV R. The maximum and minimum duration and amplitude of each component of the esophageal lead electrocardiogram are given in tabular form. A comparative study of brass and nickel-silver esophageal lead electrodes shows that there are at most minute differences in the records obtained with each type. Brass electrodes appear suitable for use as esophageal lead electrodes.