To the Editor-Atropine: Hero or villain in cardioneuroablation?

We want to congratulate the authors for their case report, stressing their dedication to obtaining the best treatment for the patient; however, there was a relapse after supposed successful cardioneuroablation (CNA). Several reasons should be considered.

First, unfortunately, atropine at CNA beginning was the villain of this case. Unfortunately, the residual effect of atropine, a powerful vagal blocker, hampered the authors’ work, masking denervation that was poor enough to allow rapid reinnervation. Nevertheless, diagnostic atropine testing may be a hero if made not less than 2 days before. Case atropine is accidentally administered at CNA beginning the procedure must not be performed.

Second, denervation confirmation during CNA by extracardiac vagal stimulation is essential. Cardiac innervation is extensive, far beyond the ganglionated plexi (GP), and long-term denervation depends on the denervation validation. CNA must be finished only after complete vagal response abolishment, and no CNA may be considered successful without this confirmation as the main endpoint. In case of residual vagal response, CNA must be expanded, ablating additional atrial fibrillation nests,4, 5, 6 until complete abolishment. Residual innervation must be disclosed to the patient, as reinnervation/recurrence may occur.

Third, it is impossible to stimulate GP by high-frequency stimulation with 1–20 millivolts. It is likely a typing error. We have abandoned CNA controlled by high-frequency stimulation because extracardiac vagal stimulation typically shows intense residual vagal response in these cases.

Fourth, high heart rate from the beginning suggests the undesirable residual atropine effect hampering the authors’ work.

Finally, for lasting denervation, additional P-point and Waterston’s groove ablation must always be performed., A huge number of micro-GPs exist in these areas.