Wiley Acta Medica Okayama 2047-9980 9 23 2020 Significance of Exercise-Related Ventricular Arrhythmias in Patients With Brugada Syndrome e016907 EN Hiroshi Morita Department of Cardiovascular Therapeutics, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Saori T. Asada Department of Cardiovascular Medicine, Okayama University Graduate School of Medicine and Dentistry Masakazu Miyamoto Department of Cardiovascular Medicine, Okayama University Graduate School of Medicine and Dentistry Yoshimasa Morimoto Department of Cardiovascular Medicine, Okayama University Graduate School of Medicine and Dentistry Tomonari Kimura Department of Cardiovascular Medicine, Okayama University Graduate School of Medicine and Dentistry Tomofumi Mizuno Department of Cardiovascular Medicine, Okayama University Graduate School of Medicine and Dentistry Koji Nakagawa Department of Cardiovascular Medicine, Okayama University Graduate School of Medicine and Dentistry Atsuyuki Watanabe Department of Cardiovascular Medicine, Okayama University Graduate School of Medicine and Dentistry Nobuhiro Nishii Department of Cardiovascular Therapeutics, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Hiroshi Ito Department of Cardiovascular Medicine, Okayama University Graduate School of Medicine and Dentistry Background Sinus tachycardia during exercise attenuates ST‐segment elevation in patients with Brugada syndrome, whereas ST‐segment augmentation after an exercise test is a high‐risk sign. Some patients have premature ventricular contractions (PVCs) related to exercise, but the significance of exercise‐related PVCs in patients with Brugada syndrome is still unknown. The objective of this study was to determine the significance of exercise‐related PVCs for predicting occurrence of ventricular fibrillation (VF) in patients with Brugada syndrome. Methods and Results The subjects were 307 patients with Brugada syndrome who performed a treadmill exercise test. We evaluated the occurrence of PVCs at rest, during exercise and at the peak of exercise, and during recovery after exercise (0–5 minutes). We followed the patients for 92±68 months and evaluated the occurrence of VF. PVCs occurred in 82 patients (27%) at the time of treadmill exercise test: PVCs appeared at rest in 14 patients (4%), during exercise in 60 patients (20%), immediately after exercise (0–1.5 minutes) in 28 patients (9%), early after exercise (1.5–3 minutes) in 18 patients (6%), and late after exercise (3–5 minutes) in 12 patients (4%). Thirty patients experienced VF during follow‐up. Multivariable analysis including symptoms, spontaneous type 1 ECG, and PVCs in the early recovery phase showed that these factors were independently associated with VF events during follow‐up. Conclusions PVCs early after an exercise test are associated with future occurrence of VF events. Rebound of vagal nerve activity at the early recovery phase would promote ST‐segment augmentation and PVCs in high‐risk patients with Brugada syndrome. No potential conflict of interest relevant to this article was reported.

Elsevier Acta Medica Okayama 09726292 20 1 2020 Repeated misclassifications of tachycardia by an implantable cardiac defibrillator 35 38 EN Atsuyuki Watanabe Department of Cardiovascular Medicine, Okayama University Osamu Fujimura Department of Cardiovascular Medicine, Okayama University This case describes repeated misclassifications of SVT due to AV node reentry as VT by an ICD. This case illustrates the limitations of SVT-VT discrimination algorithm. Careful analysis of the stored tracings is of critical importance to reach the correct diagnosis. No potential conflict of interest relevant to this article was reported.

Elsevier Acta Medica Okayama 22140271 5 10 2019 Open chest epicardial mapping in an asymptomatic patient with Brugada syndrome 501 504 EN Atsuyuki Watanabe Department of Cardiovascular Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Hiroshi Morita Department of Cardiovascular Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Satoshi Kawada Department of Cardiovascular Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Motomi Tachibana Department of Cardiovascular Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Yoshimasa Morimoto Department of Cardiovascular Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Hiroshi Ito Department of Cardiovascular Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University No potential conflict of interest relevant to this article was reported.