• Research & Clinical Studies

    Indications and Potential Adverse Effects


    Transesophageal Cardiac Pacing and Recording is indicated for:

    Temporary acceleration of heart rate to treat bradycardia (Clinical Studies);

    Acceleration of heart rate as an alternative to exercise or drugs during cardiac procedures such as echocardiography or radionuclide ventriculography (Clinicals);

    Antitachycardia pacing for cardioversion of supraventricular tachycardia (SVT), including atrial flutter and re-entrant atrial or atrio-ventricular paroxysmal tachycardia (Clinicals);

    Recording or monitoring of the esophageal electrocardiogram in the evaluation of atrial activity or differential diagnosis of complex arrhythmias (Clinicals).

    Potential Adverse Effects:

    Discomfort ("heartburn") which normally ceases instantly when pacing is discontinued.

    Gagging, choking or nausea.

    Possible injury to esophageal mucosa if total pacing duration exceeds 1 hour.

    Induction of atrial flutter, atrial or ventricular fibrillation at rapid atrial pacing rates.

    Atrial fibrillation with rapid ventricular response in patients with pre-excitation syndrome.


    Do not use in patients with esophageal injury or disease.

    Do not use as a life supporting or life sustaining device.

    Do not pace patients with complete AV heart block.

    Do not pace patients with chronic atrial fibrillation.

    Minimization of Potential Adverse Effects:

    Discomfort during pacing is correlated with pacing current, which can be minimized with proper positioning of esophageal electrodes (Positioning Electrodes).

    Gagging or choking during insertion and discomfort during pacing may be reduced with application of a lubricant and topical anesthetic prior to insertion of esophageal catheter.

    Severe coughing during insertion may be due to tracheal irritation; withdraw catheter and re-insert in the esophagus while patient sips water through a straw.

    Cardiac procedures should only be performed in medical environments where emergency defibrillation equipment is available.

    Risk of Esophageal Injury:

    There are no cases published in the medical literature or reported to CardioCommand, Inc. of esophageal injury associated with transesophageal atrial pacing.

    Pacing output of CardioCommand's Models 2-A and 7-A Transesophageal Cardiac Stimulators is voltage limited at 80V, which restricts the delivered energy to a maximum of .032 Joules/pulse. Investigators have used higher energy esophageal electrostimulation (20-100 Joules/pulse) for successful atrial and ventricular defibrillation in both animal experiments and human clinical trials without serious complications. These studies indicate that the risk for esophageal injury is negligible with low energy, temporary atrial pacing:

    Transesophageal defibrillation: animal studies and preliminary clinical observations. Cohen TJ, Chin MC, Oliver DG, Scheinman MM, Griffin JC. University of California, San Francisco. Pacing Clin Electrophysiol 1993 Jun;16(6):1285-92. Abstract

    Elective countershock in unanesthetized patients with use of an esophageal electrode. McNally EM, Meyere EC, Langendorf R. Michael Reese Hosp, Chicago. Circulation 33:124-127, 1966. Abstract

    Transesophageal cardioversion. McKeown PP, Croal S, Allen JD, Anderson J, Adgey AA. Royal Victoria Hospital, Belfast. Am Heart J 1993 Feb;125(2 Pt 1):396-404 Abstract

    Transoesophageal versus transchest DC cardioversion. Cochrane DJ, McEneaney DJ, Anderson JM, Adgey AA. Royal Victoria Hospital, Belfast. Q J Med 1993 Aug;86(8):507-11. Abstract

    Cardioversion of tachycardias by transesophageal atrial pacing. Montoyo JV, Angel J, Valle V, Gaus C. Ciudad Sanitaria de la Seguridad S. Am J Cardiol 1973 Jul;32(1):85-90. Abstract

    Transesophageal low-energy synchronous cardioversion of atrial flutter/fibrillation in the dog. Yamanouchi Y, Kumagai K, Tashiro N, Hiroki T, Arakawa K. Fukuoka University, Japan. Am Heart J 1992 Feb;123(2):417-20. Abstract

    Transesophageal low-energy cardioversion in an animal model of life-threatening tachyarrhythmias. Yunchang C, Shoulian F, Duanxing G, Shixiang G, Jifent F, Zhushen K, Zhougfan L. Guizhou Provincial Cardiovascular Institute, Republic of China. Circulation 1989 Nov;80(5):1354-9. Abstract