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Brain & Heart Cardioneuroablation for VMB

the most common electrocardiographic manifestations of rate had increased by more than 25% from the baseline
this condition. 3 rate, and no sinus arrest was recorded for 30 min following
VMB represents a significant clinical challenge due to its intravenous atropine administration.
diverse manifestations and the limited therapeutic options Before the CNA procedure, a detailed diagnostic
available for patients with severe or recurrent symptoms. evaluation is conducted to exclude patients who are not
Although lifestyle modifications and medications may suitable for the procedure. The exclusion criteria include
benefit some patients, these interventions often fail to the following: (i) structural heart or cardiopulmonary
adequately control symptoms in those with significant conditions, such as valvular heart abnormalities, severe
autonomic imbalances. Traditionally, after excluding aortic stenosis, history of myocardial infarction, pulmonary
secondary factors such as medications and internal embolism, pulmonary hypertension, or hypertrophic
environmental influences, pacemaker implantation has obstructive cardiomyopathy; (ii) cardiac rhythm
been the most common treatment for severe VMB. disturbances, including paroxysmal supraventricular
4,5
While pacemakers effectively address the symptomatic tachycardia, ventricular tachycardia, or arrhythmias
bradycardia, they do not target the underlying autonomic induced by medication; (iii) neurological conditions
dysfunction, leaving patients reliant on device-based involving the cerebrovascular system, such as subclavian
therapy. steal syndrome or seizures; (iv) syncope associated
with medications, including vasodilators, antipsychotic
Cardioneuroablation (CNA) is a specialized catheter drugs, or antidiabetic agents. Furthermore, patients with
ablation technique that specifically targets the ganglionated terminal conditions or those classified as New York Heart
plexi (GPs), which are intrinsic structures located Association Class III or IV heart failure were also excluded.
within the epicardial atrial fat pads, connecting pre- and
post-ganglionic nerve fibers. By targeting the GPs, this The CNA procedure was performed under conscious
technique helps to treat reflex syncope or functional sedation. Three-dimensional electroanatomic mapping of
bradycardia. 6-29 Through modulation of the autonomic the left atrium (LA) and pulmonary veins was conducted
pathways responsible for bradyarrhythmia, CNA offers the using the EnSite NavX system (St. Jude Medical, Saint
potential to restore balanced autonomic tone and alleviate Paul, MN, USA). The right anterior GP (RAGP), located
symptoms without reliance on permanent pacing. in the superoanterior region around the root of the right
superior pulmonary vein, was identified and marked
CNA is considered for patients with symptoms due based on anatomical relationships and local fractionated
to excessive parasympathetic activity, which leads to electrograms (Figure 1A). Ablation of the RAGP was
significantly slower heart rates (bradycardia) and other performed using a 4-mm-tip radiofrequency ablation
rhythm disturbances that are resistant to conventional catheter, with power and temperature limits set to 40 W
therapies, such as medications or pacemaker implantation. and 60°C, respectively. Clustered ablations were delivered
Here, we report two cases of patients with VMB (one with for 90 s at each site. As shown in Figures 1A and 1B, the
intermittent sinus arrest and the other with severe sinus intermittent sinus arrest and junctional escape rhythm
bradycardia), who achieved good therapeutic outcomes immediately terminated during RAGP ablation, and the
following CNA. In addition, we conducted a systematic heart rate increased to 70 bpm.
review and meta-analysis to evaluate the effects of CNA in
patients with VMB. During a 26-month follow-up, the patient experienced
no recurrence of syncope or pre-syncope. Follow-up
2. Case presentations Holter data showed no episodes of sinus arrest.
2.1. Case 1 2.2. Case 2
A 33-year-old woman presented with a 5-month history of A 42-year-old man presented with an 8-month history
recurrent dizziness and syncope. A 24-h Holter monitors of recurrent dizziness and pre-syncope. The 24-h Holter
revealed intermittent sinus arrest and junctional escape monitoring showed sinus bradycardia, with a mean
rhythm. No abnormalities were detected by transthoracic heart rate of 51 bpm (range: 29 – 92 bpm). An atropine
echocardiography, chest X-ray, or blood tests (including test confirmed an increase in the sinus rate by more than
routine blood work, electrolytes, liver and kidney functions, 25% from the baseline rate. The patient’s deceleration
troponin I, troponin T, and thyroid function). Cardiac capacity was measured at 16.5 ms. The CNA procedure was
autonomic function was assessed using the deceleration performed under conscious sedation. Three-dimensional
capacity calculated from Holter data, which yielded a high electroanatomic mapping of the right atrium (RA) was
value of 30 ms. An atropine test confirmed that the sinus conducted using the EnSite NavX system (St. Jude Medical,

Volume 3 Issue 1 (2025) 2 doi: 10.36922/bh.4824