Could Brugada Syndrome Be Treated With Percutaneous Coronary Intervention?　― Reply ―

Thank you for reading our guideline and for your kind comments. As Dr. Lim pointed out, abnormality of the conus region at the right ventricular outflow tract (RVOT) is important for considering the mechanism responsible for the Brugada pattern and lethal arrhythmias. Because the intrinsic transient outward current (I_to) is high at the RVOT, acute myocardial infarction or ischemia by injection of contrast medium etc. at the RVOT produces ST-segment elevation mimicking Brugada syndrome due to a decrease in the inward I_Ca-L and an increase in the outward I_K-ATP during ischemia.¹ Catheter ablation is an attractive modality to treat Brugada syndrome.² In addition, percutaneous conus and right ventricular acute marginal branch embolization with microbeads could be an alternative technique. Regarding the male predominance in Brugada syndrome, both an intrinsically higher I_to at the RVOT in men than women in experimental study³ and higher testosterone concentrations in men than women⁴ have been reported to contribute to the male predominance in Brugada syndrome.

We recognize that the coexistence of electrical and structural factors in Brugada syndrome is a very interesting topic. However, the guideline focuses on diagnosis and is designed to be widely used by general internists.⁵ The guideline was not written from the viewpoint of discussing mechanisms or treatment. Although the guideline does not cover these considerations in Brugada syndrome, we appreciate your supplemental letter. In particular, comments on concept of mystery as “a man’s heart stops, while a woman’s heart breaks” is very impressive for the readers of our guideline. We express sincere gratitude for you and your very kind comments again.

Disclosures

T.I. and W.S. are members of Circulation Journal’s Editorial Team.

• Bonpei Takase, MD, PhD, FJCS
• Nobuyuki Masaki, MD, PhD
• Takanori Ikeda, MD, PhD, FJCS
• Wataru Shimizu, MD, PhD, FJCS
• Department of Intensive Care Medicine, National Defense Medical College, Tokorozawa (B.T., N.M.); Division of Cardiology, Iruma Heart Hospital, Iruma (B.T.); Department of Cardiovascular Medicine, Toho University Faculty of Medicine, Tokyo (T.I.); and Department of Cardiovascular Medicine, Nippon Medical School, Tokyo (W.S.), Japan

References

• 1.   Shimizu W. Acquired forms of the Brugada syndrome. J Electrocardiol 2005; 38: 22–25.
• 2.   Nademanee K, Chung FP, Sacher F, Nogami A, Nakagawa H, Jiang C, et al. Long-term outcomes of Brugada substrate ablation: A report from BRAVO (Brugada Ablation of VF Substrate Ongoing Multicenter Registry). Circulation 2023; 147: 1568–1578.
• 3.   Di Diego JM, Cordeiro JM, Goodrow RJ, Fish JM, Zygmunt AC, Pérez GJ, et al. Ionic and cellular basis for the predominance of the Brugada syndrome phenotype in males. Circulation 2002; 106: 2004–2011.
• 4.   Shimizu W, Matsuo K, Kokubo Y, Satomi K, Kurita T, Noda T, et al. Sex hormone and gender difference: Role of testosterone on male predominance in Brugada syndrome. J Cardiovasc Electrophysiol 2007; 18: 415–421.
• 5.   Takase B, Ikeda T, Shimizu W, Abe H, Aiba T, Chinushi M, et al. JCS/JHRS 2022 guideline on diagnosis and risk assessment of arrhythmia. Circ J 2023, doi:10.1253/circj.CJ-22-0827.