@article{oai:repo.qst.go.jp:00049045,
 author = {Amino, Mari and Yoshioka, Kouichirou and Furusawa, Yoshiya and Tanaka, Sachie and Kawabe, Noboru and Hashida, Tadashi and Tsukada, Teruyo and Izumi, Masako and Inokuchi, Sadaki and Tanabe, Teruhisa and Ikari, Yuji and 網野 真理 and 吉岡 公一郎 and 古澤 佳也},
 issue = {4},
 journal = {Pacing And Clinical Electrophysiology},
 month = {Apr},
 note = {Background: Targeted external heavy ion irradiation (THIR) of rabbit hearts 2 weeks after myocardial infarction (MI) reduced the vulnerability of fatal ventricular tachyarrhythmias (VT/VF) in association with the increased connexin43 (Cx43). Increased Cx43 was maintained for at least 1 year in normal rabbits, but the long-term antiarrhythmic effects in the MI model are unknown. We investigated the propensity for late potentials and VT/VF inducibility.
Methods: Intracoronary injection of microspheres was performed to induce nontransmural MI in anesthetized eight beagles. Four beagles were treated with THIR (12C6+, 15 Gy) 2 weeks later (MI + THIR group), and four without THIR served as controls (MI group). Signal-averaged electrocardiography, programmed electrical stimulation, immunohistochemical analysis, and echocardiograms were performed at 1 year.
Results: Filtered QRS duration was exacerbated after MI and remained unchanged for 1 year in the MI group (118 ± 1.4 ms), but significantly returned toward baseline in the MI + THIR group (109 ± 6.9 ms). Similarly, root mean square voltage of the last 40 ms was exacerbated after MI, but recovered after THIR. VT/VF inducibility decreased to 25% in the MI + THIR group compared with 100% in the MI group. Immunostaining Cx43 expression in cardiac tissues significantly increased by 24–45% in the MI + THIR group. Left ventricular ejection fractions remained within the normal range in both groups.
Conclusion: A single exposure of the dog heart to 12C irradiation attenuated vulnerability to ventricular arrhythmia after the induction of MI for at least 1 year through the modulation of Cx43 expression.},
 pages = {379--390},
 title = {Inducibility of Ventricular Arrhythmia 1 Year Following Treatment with Heavy Ion Irradiation in Dogs with Myocardial Infarction},
 volume = {40},
 year = {2017}
}