Cardioneuroablation for Recurrent Chest Pain with Syncope Secondary to Severe Coronary Artery Spasm Induced by Vagal Excitation: A Case Report

1. Background: This case is reported for its novelty in demonstrating a direct link between exaggerated vagal tone and life-threatening coronary artery spasm (CAS), leading to syncope and cardiac arrest. While vasovagal syncope is common, its manifestation as severe CAS causing ST-elevation and high-grade atrioventricular block is rare. Furthermore, this case highlights the critical role of a comprehensive diagnostic approach beyond standard coronary intervention and the successful therapeutic use of Cardioneuroablation(CNA) to prevent recurrent events, offering a potential new strategy for managing similar refractory cases. 2. Case presentation: A 53-year-old male with a significant smoking history presented with a 6-month history of recurrent, episodic substernal burning pain, triggered by heat and at night, often followed by syncope with prodromal symptoms. Initial coronary angiography revealed significant multi-vessel disease, for which he underwent percutaneous coronary intervention (PCI) with stent and drug-coated balloon（DCB） implantation. However, his symptoms persisted. He subsequently suffered a syncope event in hospital, during which ECG showed inferior ST-segment elevation and third-degree atrioventricular block. Emergency angiography revealed diffuse coronary narrowing that resolved with intracoronary nitroglycerin, confirming a diagnosis of coronary artery spasm. Medical therapy with Diltiazem and Nicorandil was initiated. A head-up tilt test was positive (mixed type), reproducing his symptoms and confirming vasovagal syncope(VVS). The final diagnosis was vagally-induced coronary artery spasm. Given the refractory nature of his condition, he underwent successful CNA. At 3-month follow-up, the patient remained free of chest pain and syncope. Then, the patient discontinued the use of Diltiazem and Nicorandil, and the 6-month follow-up remained satisfactory. 3. Conclusions: For patients with recurrent chest pain and syncope, secondary to severe CAS induced by vagal excitation, CNA may represent a effective therapeutic intervention to prevent recurrent syncope and cardiac arrest, suggesting a new method in managing such complex cases.