[Inappropriate sinus tachycardia - non-contact mapping and ablation].

Two cases of inappropriate sinus tachycardia refractory to combined pharmacotherapy (beta-blocker, ivabradine) are described. Both were female patients (28 and 45 years-old) and underwent sinus node modification/ablation using non-contact mapping (EnSite Array). Since ablation had to be performed in both cases very close to the phrenic nerve (captured during 10V pacing at ablation spots) its function was monitored during ablation with constant phrenic nerve pacing from the superior vena cava. One case was successful after single and straightforward ablation session, the other case despite several attempts and initially good result had recurrences; first recurrence two days after cryoablation, and second three weeks after radiofrequency ablation with irrigated tip catheter.