[Transesophageal atrial stimulation in 168 patients].

Transesophageal atrial stimulation was performed in 168 patients, 95 males and 73 males, 20 to 81 years of age. The indication for atrial stimulation was the study of some bradyarrhythmia in 109 and ischemic heart disease in 59. An esophageal catheter was introduced through the nose and placed at a spot where a bimodal P wave was obtained. Stimulation was performed using a baby Medtronic stimulator coupled to a Vygon amplifier delivering an output of 30 volt. Sinus node recovery time was measured after 2 to 3 min of stimulation at different rates. Wenckebach and 2:1 A-V block as well as ST deviation were determined. Sick sinus syndrome was diagnosed in 41 cases through altered sinus node recovery time and/or secondary pauses; 35 patients showed Wenckebach rhythm at a stimulation rate over 120 per min; 2: 1 A-V block appeared in 22. Ischemic ST-T changes were produced in 20 subjects. No complications were observed, confirming this approach as a simple and effective way to achieve atrial stimulation for diagnostic purposes.