Cardioneuroablation: New Program Focused on Novel Approach

In this interview, EP Lab Digest speaks with Peem Lorvidhaya, MD, Director of the Cardioneuroablation (CNA) Immersive Center at Mary Washington Healthcare in Fredericksburg, Virginia, and Spotsylvania Regional Medical Center in Spotsylvania County, Virginia.

How and when did the cardioneuroablation programs at both institutions come about?

I have long been interested in novel ways to help patients with dysautonomia (i.e., postural orthostatic tachycardia syndrome [POTS], inappropriate sinus tachycardia, and vasovagal syncope). Patients with these conditions often have poor functional status and are frequently subjected to psychological trauma from being told “there is nothing wrong” and “it’s all in your head.”

For a number of years, we have been aware of the role that ablation of ganglionic plexi (GP) or cardioneuroablation plays in atrial fibrillation (AF). In parallel to this data, centers in Brazil, China, and Turkey have produced a large number of data to support the use of CNA in vasovagal syncope, functional AV block, and sinus node dysfunction.

I have been following the trend and feasibility of CNA in the U.S. for a number of years. I did not think this could be performed in the U.S. until I came across recent research by Roderick Tung et al.¹ This jump-started my conversation with the two local hospitals where I currently practice. With the great support of administration, we started this CNA program at both institutions in February 2021.

What can you tell us about CNA and its role in the treatment of vasovagal syncope?

CNA was initially described by Jose Pachon et al in 2005 in patients with symptomatic functional bradyarrhythmias, including neurally mediated syncope.² CNA seeks to target the vagal innervation of the heart by way of targeting the GPs, which are carefully mapped in sinus rhythm through identifying fractionated potentials in areas of interest (Figure 1). These are further confirmed through positive vagal response to high-frequency stimulation (HFS) (Figures 2 and 3).

While the exact mechanism of how vasovagal syncope develops in association with vagal innervation of the heart is still not entirely clear, numerous nonrandomized studies since 2004 have described a significant improvement in patients with refractory vasovagal syncope through CNA, most likely through modification of the usual response of susceptible patients through severe bradycardia as well as possibly through peripheral vasodilatation and venous pooling.

What are the clinical benefits of CNA?

We carefully select patients who have exhausted all other standard options for the treatment of vasovagal syncope to ensure that we are providing help to patients who are most in need. In patients with refractory vasovagal syncope, we have seen an average of about 80% improvement (unpublished data) of the number of near-syncope or frank syncope. Given that we are still in an early stage of the program, we currently do not have enough experience with patients presenting with functional AV block and/or sinus node dysfunction. Other areas of interest are the role of CNA in persistent AV block after completion of antibiotics therapy in Lyme carditis, as well as certain types of long QT syndrome.

What interests you about this novel therapy?

While most patients with dysautonomia (specifically, vasovagal syncope) respond fairly well to standard therapy (e.g., increasing salt and fluid intake, use of medications such as midodrine, pacemaker implantation), a smaller group of patients remain highly refractory. CNA allows a large percentage of refractory patients to regain their quality of life.

Tell us more about the CNA program staff as well as caseload.

The CNA program is primarily located at Spotsylvania Regional Medical Center. Our staff consists of 1 EP RN, 1 EP tech, 1 circulator, as well as 1-2 mapping representative(s) per case. Between the 2 hospitals, we have 6 RNs, 5 EP techs, and a number of industry representatives depending on the complexity of the cases.

In a typical week, we perform between 1-4 CNA procedures. At this time, we are working through a large backlog of patients with refractory vasovagal syncope. However, we are also actively looking to expand the program to include symptomatic bradyarrhythmias (functional AV block and sinus node dysfunction) in the near future.

What is your ablation approach? How are follow-up outcomes evaluated?

We map and ablate the GPs in the left and right atria through identification of fractionated electrograms as well as positive vagal response with HFS, as described by Pachon, Tolga Aksu, and others.

We typically aim to repeat a tilt table test at 3 months, 6 months, and 1 year after the procedure, in addition to follow-up visits in the office at least quarterly in the first year to assess functional status.

Can you share an interesting case from your program?

I have been working with a 55-year-old male patient for a number of years who was very refractory to aggressive medical and behavioral therapy. He would become presyncopal every time he drove over an elevated bridge and would have to strategically either avoid those types of bridges, or really focus on tightening the muscles in his legs and abdomen to prevent frank syncope. Since the day after his CNA procedure and for the last 6 months, he has not had a single episode of dizziness.

What’s next in CNA? What questions remain about CNA?

I foresee a significant growth of the procedure in both the U.S. and abroad. Shortly after we started our program, we were asked by Abbott to be the first (and thus far, the only) immersive site in the U.S. dedicated to the research and training for CNA. I believe the role of CNA in AF, bradyarrhythmias, and types of long QT syndrome will also be greatly expanded. Current challenges in this area include the lack of randomized trials and the potential role of CNA in other forms of dysautonomia.

Is there anything else you’d like to add?

I would love to be able to collaborate with other centers with interests in conducting research regarding the role of CNA in various clinical scenarios. I can be reached at peemlor@gmail.com. 

Disclosures: Dr. Lorvidhaya has no conflicts of interest to report regarding the content herein. He reports honoraria from Abbott in relation to the Cardioneuroablation Immersive Center with visiting physicians.

References

1. Lu Y, Wei W, Upadhyay GA, Tung R. Catheter-based cardio-neural ablation for refractory vasovagal syncope: first U.S. report. JACC: Case Rep. 2020;2(8):1161-1165. doi: 10.1016/j.jaccas.2020.04.022

2. Pachon JC, Pachon EI, Pachon JC, et al.  “Cardioneuroablation” – new treatment for neurocardiogenic syncope, functional AV block and sinus dysfunction using catheter RF-ablation. EP Europace. 2005;7(1):1-13. doi: 10.1016/j.eupc.2004.10.003