LONG-TERM REPRODUCIBILITY OF THE RESULTS OF PROGRAMMED ATRIAL STIMULATION

Programmed atrial stimulation is a technique increasingly used to asse ss different pathologies but the reproducibility of the results is tot ally unknown. The aim of this study was to determine its reproducibili ty. Two electrophysiological studies were undertaken without antiarrhy thmic therapy in an interval of one to three months (average 18 months ) in 48 patients. The programmed atrial stimulation used 1 and 2 extra stimuli delivered in sinus rhythm and then three paced rhythms (sinus cycle -10%, 600 ms, 400 ms). Twenty-one patients had documented atrial arrhythmias (atrial fibrillation n = 13, flutter n = 3 or tachycardia n = 5) (group I) and the 27 other patients had no spontaneous arrhyth mias (group II). In group I, clinical tachycardial was reproduced in 1 8 patients during the initial stimulation procedure. During the second investigation, 17 remained inducible and in the 3 in whom stimulation was negative, it remained so in 2 of the cases. The reproducibility w as therefore 90%. In group II, 12 patients had inducible sustained (fo r over 1 minute) tachycardia during the first procedure (44%) but this only remained inducible in 6 patients. In the other 15 subjects, stim ulation was negative during the first procedure but 7 of them had indu cible tachycardial during the second procedure. The reproducibility of the technique was therefore only of 52%. The authors conclude that th e reproducibility of programmed atrial stimulation in patients with do cumented spontaneous paroxysmal arrhythmias is excellent. However, the reproducibility is mediocre in subjects without spontaneous arrhythmi as and the induction of tachycardial in this group of patients should be interpreted with caution given the variability of the response to p rogrammed atrial stimulation.