Treatment of supraventricular tachycardias by rapid atrial stimulation

In 10 patients, 24 episodes of supraventricular tachycardia were treated by rapid electrical stimulation of the right atrium. One episode of sinus tachycardia, eight episodes of atrial tachycardia, two episodes of atrial flutter, and 13 episodes of A-V junctional tachycardia occurred. In each case the diagnosis of the arrhythmia was documented by obtaining unipolar and bipolar intra-atrial electrograms. In three cases of supraventricular tachycardia the ventricular rate was slowed as a result of an increased atrial rate. The increased atrial rate caused an increase of the functional refractory period of the A-V junction, and thus, fewer atrial impulses were transmitted to the ventricles. In seven cases, 21 episodes of supraventricular tachycardia were terminated by rapid atrial stimulation. In six of these cases the tachycardia was converted to normal sinus rhythm either during or shortly after atrial stimulation. In one case, 12 episodes of A-V junctional tachycardia were converted to rhythms varying between normal sinus rhythm and a slow A-V junctional rhythm. In this case, after termination of the last episode of A-V junctional tachycardia, the rhythm was stabilized by atrial pacing.