Lead configurations in esophageal electrocardiography

There are many clinical situations that present the need for special purpose electrocardiography using standard equipment. These include monitoring cardiac activity from temporary myocardial leads implanted following cardiac surgery, detecting signals from intracardiac catheter leads, and noninvasive atrial recording from the esophagus. It is often difficult to connect nonstandard leads and access the individual amplifiers. In this article, we present the case for an esophageal electrode such as the Pill Electrode (Arzco Medical Electronics, Inc., Chicago, IL). We describe several configurations for connecting this electrode to electrocardiographs and comment on the merits and shortcomings of each method.