Akiko Nishizaki

Optimal Titration Is Important to Maximize the Beneficial Effects of Vagal Nerve Stimulation in Chronic Heart Failure

BACKGROUND Although vagal nerve stimulation (VNS) benefits patients with chronic heart failure (CHF), the optimal dose of VNS remains unknown. In clinical trials, adverse symptoms limited up-titration. In this study, we evaluated the impact of various voltages of VNS which were titrated below symptom threshold on cardiac function and CHF parameters in rat myocardial infarction (MI) models. METHODS AND RESULTS We randomly allocated MI rats to vagal (VNS; n = 41) and sham (Sham; n = 16) stimulation groups. We stimulated the right vagal nerve with 20 Hz at 3 different voltages for 4 weeks. We defined Max as the highest voltage that did not evoke any symptom, Half as one-half of Max, and Quarter as one-fourth of Max. All 3 VNS groups significantly reduced biventricular weight compared with Sham (P < .05). In contrast, only Half decreased left ventricular (LV) end-diastolic pressure (Half: 17.5 ± 2.0 mm Hg; Sham: 24.2 ± 1.2 mm Hg; P < .05) and increased LV ejection fraction (Half: 37.9 ± 3.1%; Sham: 28.4 ± 2.3%,-P < .05) and LV maximum +dP/dt (Half: 5918.6 ± 2.0 mm/Hg/s; Sham: 5001.2 ± 563.2 mm Hg/s; P < .05). The number of large vagal nerve fibers was reduced with Max (Max: 163.1 ± 43.0 counts/bundle; Sham: 360.0 ±61.6 counts/bundle; P < .05), indicating significant neural damage by VNS. CONCLUSION The optimal titration of VNS would maximize benefits for CHF and minimize adverse effects.

Crystallization granuloma by nifekalant hydrochloride infusion

Tomoko Yamada, Shin-ichiro Iwakami, Sumiko Abe Munechika Hara, Naoko Iwakami, Ai Nakamura, Yoshifumi Suzuki, Shin-ichi Sasaki and Kazuhisa Takahashi Department of Respiratory Medicine, Juntendo University Graduate School of Medicine, Tokyo, Japan Department of Respiratory Medicine, Juntendo University Shizuoka Hospital, Shizuoka, Japan Department of Respiratory Medicine, Juntendo University Urayasu Hospital, Chiba, Japan References

Refractory coronary artery spasm associated with tacrolimus

A 51-year-old man presented with recurrent chest pain at rest, accompanied by transient ST elevation on ECG (Fig. 1). At the age of 47 years, he had been diagnosed with multivessel coronary artery spasm (CAS), which was under control because the patient had been taking nifedipine, isosorbide dinitrate, and nicorandil. Twelve days before the patient was referred to our clinic, he had been diagnosed with severely active ulcerative colitis (UC) and treated with high-dose steroids (60mg/day). Six days before referral to our clinic, his diarrhea and bloody stools had not improved; therefore, he was prescribed tacrolimus 8mg/day, which has been proven to be an effective alternative treatment option to surgery in patients with steroid-refractory UC. His chest pain and ECG changes resolved immediately in response to sublingual nitroglycerin, but spontaneous ischemic attacks occurred more than 10 times per day. His clinical features were compatible with worsening CAS triggered by tacrolimus, and tacrolimus was withdrawn. To ensure prevention of spastic attack, oral nifedipine was switched to benidipine; in addition, an intravenous diltiazem was administered. Oral