LAUSR

An 18-year-old female with Ehlers Danlos syndrome and severely intrusive symptoms related to inappropriate sinus tachycardia (IST) despite multiple medications had previously undergone 2 sinus node modifications with limited success. The first procedure used cryo-ablation and the second radiofrequency ablation. Despite intra procedural heart rate slowing, patient symptoms recurred soon after the ablation and she was scheduled for a repeat attempt at sinus node modification using a novel multi electrode mapping catheter. A zero fluoroscopy case was performed using the Precision/ NavX system (Abbott, USA). Initial right atrial geometry was initially collected with a Tacticath (F-curve) irrigated 4mm ablation catheter (Abbott, USA). A quadripolar catheter was placed in coronary sinus and a novel 16-polar multi electrode catheter (high density, HD grid, Abbott, USA) used for further geometry collection alongside rapid point collection for simultaneous activation times and a voltage map. A total of 931 points were taken during the map (<5 minutes). Baseline sinus rhythm cycle length was 750m s. Previous ablation lesions denoted by low voltage were noted in the high right atrium (Fig. 1A). During sinus rhythm the earliest signal