Multiple multisite low-temperature and low-power radiofrequency currents for the induction of atrioventricular nodal reentry tachycardia in non-inducible patients.

AIMS: Some patients with documented episodes of paroxysmal supraventricular tachycardia (PSVT) do not have inducible tachycardia during the electrophysiological study. In this study, we describe how multiple low-temperature, low-power radiofrequency (RF) currents in the atrioventricular (AV) junction region can increase the rate of the induction of atrioventricular nodal reentrant tachycardia (AVNRT) in non-inducible cases.
METHOD: We enrolled 31 consecutive patients (mean age = 50.9 ± 11.9 years; 5 [16.1 %] male) who presented with documented clinical PSVT in superficial electrocardiography but had non-inducible arrhythmia in the electrophysiology laboratory despite applying different stimulation protocols. We delivered low-power (25 W), low-temperature (45 °C) RF currents into the AV junction region to induce AVNRT.
RESULTS: Arrhythmia was induced in 20 (64.5 %) patients, and it was non-sustained in 3 (9.6 %) patients. RF current was delivered into the posterior region near the coronary sinus ostium and midseptal region. RF ablation target in inducible patients was the non-inducibility of the AVNRT at the end of the procedure, while the target in the non-inducible patients was slow pathway ablation with no antegrade conduction over the slow pathway. During the follow-up period, none of the patients (either with inducible or non-inducible arrhythmia) had recurrence of AVNRT.
CONCLUSION: Multiple low-power, low-temperature RF current application into the AV junction region is a more effective method for the induction of AVNRT in comparison with a single current use into the slow pathway.