23). Letter to the editor

Letters to the Editor will be published, if suitable, and as space permits. They should not exceed 1,000 words (typed double spaced) in length, and may be subject to editing or abridg-ment. Prinzmetal's Angina Pectoris To the Editor: A very interesting paper by Yasue and associates concerning the role of the autonomic nervous system in the pathogenesis of Prinzmetal's angina pectoris appeared in the September 1974 issue of Circulation. The authors report their ability to precipitate at-tacks of angina pectoris with the choline ester methacholine and were able to block this response by prior administration of atropine. Although the authors did not demonstrate coronary artery spasm in their patients at the time of coronary arteriography, the literature now contains enough reports of non-catheter-induced spasm in the large coronary vessels in individuals with this syndrome to support Prinz-metal's original thoughts about the etiology of this un-usual and interesting form of angina pectoris. Aside from the obvious therapeutic implications of parasympathetic triggering of coronary artery spasm, it is quite possible that many episodes of coronary artery spasm which would otherwise be noted at the time of coronary arteriography are thwarted by prior administration of atropine which many cardiovascular laboratories give prior to injecting the coronary arteries in order to diminish bradycardia. In view of this possibility it is our feeling that the routine use of atropine prior to coronary arteriography should be re-examined, particularly in patients with suspected variant form of angina pectoris