Tsutomu Saitoh, MD; Hiroshi Kishida, MD; Aya Hanashi, MD; Yayoi Tsukada, MD; Yumiko Fukuma, MD; Junko Sano, MD; Nagaharu Fukuma, MD; Yoshiki Kusama, MD; Hirokazu Hayakawa, MD

Abstract
The relationship between autonomic nervous system activity (ANA) and coronary vasoreactivity during tran-sient myocardial ischemia was determined in patients with vasospastic angina (VA). ANA was measured by power spectral analysis of heart rate variability and humoral factors following intravenous infusion of insulin in 24 patients with VA and 6 control patients. Nine (38%) of the VA patients had significant ST segment depres-sion (STD), and 4 of these patients had symptomatic STD. The frequency of anginal episodes in the 9 patients with VA and STD was significantly greater than that in the 15 VA patients without STD (3.4±3.1 vs 0.5±0.8 episodes/week, p<0.05). The increase in the LF/HF ratio 30min after insulin injection in patients with STD was significantly greater than that in patients without STD (34±31% vs 4±34%, p<0.05). All of the patients with VA and STD had significant coronary vasospasm in response to the infusion of ²20µ g of acetylcholine, higher levels of nocturnal parasympathetic activity, and greater norepinephrine production in response to insulin stimulation than the VA patients without STD. These findings suggest that increased vagal tone and hyperreactivity to adren-ergic stimulation may trigger vasospasm in patients with VA.
(Jpn Circ J 1998; 62: 721-726)

Key Words: Autonomic nervous system activity; Coronary vasospasm; Vasospastic angina

Mailing address: Tsutomu Saitoh, MD, First Department of Internal Medicine, Nippon Medical School, 1-1-5 Sendagi Bunkyo-ku, Tokyo, 113-8603, Japan. E-mail: centerts@mail.246.ne.jp