Reliable focal and rotational activations in CARTOFINDER mapping using the OctaRay catheter.

INTRODUCTION: The aim of the current study was to elucidated the reliable atrial fibrillation (AF) drivers identified by CARTOFINDER using OctaRay catheter. METHODS AND RESULTS: The reliability of focal and rotational activations identified by CARTOFINDER using OctaRay catheter was assessed by the sequential recordings in each site of both atrium before and after pulmonary vein isolation (PVI) in 10 persistent AF patients. The outcome measures were the reproducibility rate during the sequential recordings and the stability rate between pre- and post-PVI as reliable focal and rotational activations. The study results were compared with those under use of PentaRay catheter (N = 18). Total 68928 points of 360 sites in OctaRay group and 24 177 points of 311 sites in PentaRay were assessed. More focal activation sites were identified in OctaRay group than PentaRay group (7.9% vs. 5.7%, p < .001), although the reproducibility rate and the stability rate were significantly lower in OctaRay group (45.3% vs. 58.9%, p < .001; 11.2% vs. 28.4%, p < .001). Meanwhile, the prevalence of reproducible focal activation sites among overall points was comparable (3.6% vs. 3.3%, p = .08). Regarding rotational activation, more rotational activation sites were identified in OctaRay group (5.1% vs. 0.2%, p < .001), and the reproducibility rate and the stability rate were significantly higher in OctaRay group (45.2% and 12.5% vs. 0.0%, p < .001). Both reliable focal and rotational activation sites were characterized by significantly shorter AF-cycle length (CL) and higher repetition of focal and rotational activations during the recordings compared with the sites of non or unreliable focal and rotational activations. CONCLUSION: In CARTOFINDER, OctaRay catheter could identify reliable focal activation with high resolution and reliable rotational activation compared with PentaRay catheter. The repetitive focal and rotational activations with short AF-CL could be the potential target during ablation.

Decrease in current perception thresholds of A-beta fibers by subthreshold noise stimulation using transcutaneous electrical nerve stimulation.

Developing effective supplements and rehabilitation of the impaired tactile and proprioception sensation is a significant challenge. One potential method for improving these sensations in clinical practice is using stochastic resonance with white noise. While transcutaneous electrical nerve stimulation (TENS) is a simple method, the effect of subthreshold noise stimulation via TENS on sensory nerve thresholds is currently unknown. This study aimed to investigate whether subthreshold TENS can alter afferent nerve thresholds. The electric current perception thresholds (CPT) of A-beta, A-delta, and C fibers were assessed in 21 healthy volunteers during both subthreshold TENS and control conditions. Subthreshold TENS was found to have lower CPT values compared to the control condition for A-beta fibers. No significant differences were observed between subthreshold TENS and control for A-delta and C fibers. Our findings indicated that subthreshold TENS might selectively enhance the function of A-beta fibers.