| Title | Exaggerated Reactivity of Parasympathetic Nerves Is Involved in Ventricular Fibrillation in J-Wave Syndrome. | ||
| Author | Shinohara, Tetsuji; Kondo, Hidekazu; Otsubo, Toyokazu; Fukui, Akira; Yufu, Kunio; Nakagawa, Mikiko; Takahashi, Naohiko | ||
| Journal | J Cardiovasc Electrophysiol | Publication Year/Month | 2017-Mar |
| PMID | 27885745 | PMCID | -N/A- |
| Affiliation | 1.Department of Cardiology and Clinical Examination, Faculty of Medicine, Oita University, Oita, Japan. | ||
INTRODUCTION: Brugada syndrome (BrS) and early repolarization syndrome (ERS) are termed the J-wave syndrome. In most cases of J-wave syndrome, ventricular fibrillation (VF) often occurs around midnight or in the early morning when parasympathetic tone is augmented. OBJECTIVE: The purpose of this study was to clarify the relationship between VF and autonomic nervous activity in patients with J-wave syndrome. METHODS AND RESULTS: We enrolled 28 consecutive patients with J-wave syndrome (20 BrS and 8 ERS) in whom implantable cardioverter defibrillators (ICDs) were implanted between January 2002 and December 2014. Eleven patients (39%) experienced ICD shock delivery due to VF recurrence after ICD implantation (recurrent-VF group). We investigated baroreflex sensitivity (BRS) using the phenylephrine method, heart rate variability (HRV) with Holter electrocardiography, plasma levels of norepinephrine, and cardiac (123) I-metaiodobenzylguanidine (MIBG) scintigraphy to estimate autonomic nervous function. Upon measurement of HRV, plasma levels of norepinephrine, and (123) I-MIBG testing, there was no significant difference between recurrent-VF and nonrecurrent-VF groups. However, BRS was significantly higher in the recurrent-VF group than in the nonrecurrent-VF group (P = 0.03). Kaplan-Meier curves suggested that high-BRS patients had higher VF recurrence than those with nonhigh-BRS (P = 0.04). Cox proportional hazards regression analyses showed that high BRS was associated independently with VF recurrence (P = 0.002). CONCLUSIONS: Our results suggest that exaggerated reactivity of parasympathetic nerves, as represented by increased BRS, may underlie VF in patients with J-wave syndrome.