title: Esophageal electrocardiography in acute cardiac care. Efficacy and diagnostic value of a new technique.
abstract: Esophageal electrocardiography can detect atrial electrical activity during tachyarrhythmias when P waves are not evident by surface electrocardiography. However, patient discomfort, the difficulty of accurately interpreting cardiac signals against a background of electrical noise, and the complexity of use have limited widespread application. In this study, esophageal electrocardiography was used in 48 acutely ill patients with a new "pill electrode" system, consisting of a bipolar electrode pair (3 by 20 mm) attached to 0.5 mm diameter Teflon wires contained in a standard gelatin capsule. The capsule with enclosed electrodes was voluntarily swallowed, and the recording electrodes were positioned posterior to the left atrium. A preamplifier system with a low-frequency filter and a standard three-channel electrocardiographic recorder were used. Esophageal "pill" electrocardiographic recordings were made in 48 of 50 eligible study patients (96 percent) with tachyarrhythmias and absent or equivocal atrial activity on surface electrocardiography. In these patients, a high-quality esophageal electrocardiographic recording was obtained within one to 10 minutes with minimal patient discomfort. In 25 of 48 study patients (52 percent), the original diagnosis, based on the surface electrocardiographic recording, was incorrect after review of the esophageal recording. Results of esophageal recording altered management in 19 of 48 (40 percent) patients. This new and simple technique facilitates diagnosis and management of perplexing tachyarrhythmias in acutely ill patients by physicians with minimal training in the technique.
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001145:Arrhythmias, Cardiac / Q000175:diagnosis; D004562:Electrocardiography / Q000295:instrumentation / Q000379:methods*; D004947:Esophagus; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013610:Tachycardia / Q000175:diagnosis