Takenaka S, Ohe T. Okayama University Medical School. Nippon Rinsho 1996 Aug;54(8):2074-9. Identification of P wave is essential for the diagnosis of various arrhythmias. The transesophageal ECG is useful for obtaining the relationship of atrial-ventricular activation when P wave is difficult to recognize on the surface ECG. Transesophageal pacing is also helpful to evaluate the function of the conduction system and to clarify the mechanism of arrhythmias. Thus, transesophageal pacing and recording can be used as beside electrophysiologic studies in patients with sick sinus syndrome, atrial-ventricular block, atrial flutter, and paroxysmal supraventricular tachycardia.