Letter by Debruyne Regarding Article, “Targets and End Points in Cardiac Autonomic Denervation Procedures”
To the Editor:
I read with interest the article by Dr Rivarola et al1 entitled Targets and End Points in Cardiac Autonomic Denervation Procedures.
The authors studied physiological changes during ablations in patients with cardioinhibitory syncope, with advanced atrioventricular block and with sinus arrest. Their procedure involved a left side ablation, targeting first the inferior right ganglionated plexus, then the anterior right ganglionated plexus followed by a right side approach targeting the right posterior and right inferior right atrium. They found that ablation at specific sites at the interatrial septum (IAS) is associated with a shortening of the R-R interval and of the Wenckebach point. The authors propose a bilateral ablation of the caudal and cranial parts of the IAS combined with a negative response to atropine as a new end point.
I agree that IAS ablation was the important step in their procedure. Whereas the authors wrote that an IAS ablation combining the left and the right approach should be preferred, their data do not support this recommendation. Indeed, as the IAS was ablated from the left side first, the right-sided approach may have been sufficient.
In my initial article on cardio-neuromodulation,2 I proposed the following:
to limit the ablation procedure to the anterior right ganglionated plexus, based solely on an anatomic approach;
to choose the P-P interval shortening as a new procedural end point; and
to tailor the amount of sinus node vagolysis to the patient’s needs.
These 3 points led us to propose the name cardio-neuromodulation.
Regarding the ideal target, I believe that selective ablation of the anterior right ganglionated plexus is sufficient in patients affected by neurally mediated syncope presenting with inappropriate bradycardia. I performed my first case through a left side approach in May 2014 and switched to a right-sided approach solely 2 months later. My long-term clinical results were accepted for publication in December 2016.3
The best end point should be associated with the smallest physiological changes that can predict a good clinical outcome. To avoid inappropriate sinus tachycardia—a potential complication of cardioneuroablation—we proposed to tailor the amount of sinus node vagolysis to the patient’s needs according to the biological response observed during ablation. The ideal amount of sinus node vagolysis still need to be defined.
Whereas we assume that cardio-neuromodulation is sufficient in patients exhibiting functional inappropriate sinus bradycardia, an additional ablation step targeting the inferior right ganglionated plexus may be needed in patients with atrioventricular block.
A better understanding of the individual function of each ganglionated plexus and of the interganglionated pathways will help us to refine our treatment strategy in patients with sinus node or atrioventricular node functional disorders.
Philippe Debruyne, MD
Department of Cardiology
Dr Debruyne has applied for a patent related to this research.
- © 2017 American Heart Association, Inc.
- Rivarola EW,
- Hachul D,
- Wu T,
- Pisani C,
- Hardy C,
- Raimundi F,
- Melo S,
- Darrieux F,
- Scanavacca M
- Debruyne P
- Debruyne P,
- Wijns W