[Transesophageal stimulation in the treatment of atrial flutter and tachysystole. Factor influencing immediate results].

The effectiveness and safety of transoesophageal atrial pacing in the treatment of atrial flutter and tachycardia have been well demonstrated. The purpose of this study was to determine the factors that could influence the results of this method at the end of the procedure. Seventy-seven transoesophageal atrial pacings were performed in 62 unselected consecutive patients with either flutter or atrial tachycardia. The following parameters could be evaluated in 55 patients: date of onset of the arrhythmia, echocardiographic diameter of the left atrium, maximum amplitude of oesophageal atrial potentials, voltage and frequency of stimuli in the last stage of pacing. Our results can be summarized as follows: In both flutter and atrial tachycardia taken globally, conversion to sinus rhythm was obtained in 37 p. 100 of the cases, and conversion to atrial fibrillation in 46.7 p. 100 of the cases. The failure rate was 19.4 p. 100; all failures were due to lack of atrial capture during pacing. The main factor or transoesophageal atrial capture is voltage. Patients must be able to tolerate the voltage needed for capture. In the case of flutter, when capture was achieved a normal-sized left atrium and a high maximum amplitude of oesophageal atrial potentials were factors indicating that conversion to sinus rhythm could be expected. This, however, did not apply to atrial tachycardia. -- Whatever the type of tachyarrhythmia, the more recent its onset the easier its reduction.