br In our experience br History of ER and

In our experience
History of ER and ACh tests As shown in Table 1, Stein et al. first reported the usefulness of intravenous injection of ER in diagnosing coronary insufficiency in 1949 [16]. In 1972, the first ER spasm provocation test was employed at the Cleveland Clinic during cardiac catheterization [17]. In contrast, Yasue et al. reported that subcutaneous injection of methacholine induced an attack of variant NS 11394 or coronary artery spasm in 1974 [18]. Subsequently, Endo reported the coronary arteriogram and ventriculogram during attack induced by methacholine in Prinzmetal's variant angina in 1976 [19]. Schroeder et al. reported the clinical result of intravenous ER testing in 57 patients in 1977 and Waters et al. also reported the ER testing in coronary care unit in 1980 [20], [21]. Curry et al. reported the similarities of ER-induced and spontaneous attacks of variant angina in 1979 [22]. Yasue et al. reported that intracoronary injection of ACh induced coronary spasm and attack in patients with variant angina and that the activity of the parasympathetic nervous system may play a role in the pathogenesis of coronary spasm in 1986 [10]. Hackett et al. and Ishise et al. reported the usefulness of intracoronary administration of ER instead of intravenous injection of ER in 1987 [8], [9]. Okumura and Yasue et al. reported that sensitivity of the intracoronary injection of ACh was 90% in variant angina and specificity of the intracoronary injection of ACh was 99%, and that multivessel coronary spasm was often observed in patients with variant angina by using intracoronary injection of ACh in 1988 [11], [12]. Since then, spasm provocation test of ACh has become a popular test for the induction of coronary artery spasm in the cardiac catheterization laboratory in Japan instead of intravenous injection of ER. The spasm provocation test is not broadly employed outside Asia, for example neither in the USA nor in Europe. In 2008, Ong et al. reported the coronary artery spasm as a frequent cause of acute coronary syndrome by using intracoronary ACh testing [23]. Recently, Ong et al. also reported the clinical usefulness of intracoronary ACh provocation tests in 921 consecutive white patients [24]. However, there are few papers about simultaneous or continuous ACh and ER tests in the same patients, because ER is not available in many countries.
Spasm provocation test of ER
Spasm provocation test of ACh
Incidence of provoked spasm by ER and ACh tests As shown in Table 4, the frequency of provoked spasm by the intravenous injection of ER was significantly lower than that by the intracoronary administration of ER and Ach [42], [43], [44], [45]. The frequency is approximately 2.5-fold higher when performed by the intracoronary administration of pharmacologic agents compared with that by unselective methods. However, there was no difference concerning the incidence of provoked spasm between ER and Ach [46]. Recently, Ong et al. reported that the provoked spasm frequency in even Caucasian white patients by performing ACh tests was similar to the incidence in Japanese patients [24]. If Caucasian cardiologists performed ACh tests routinely in the cardiac catheterization laboratory, we may understand that coronary artery spasm has no borders or no racial differences as a real truth. Asian cardiologists have been interested in performing spasm provocation tests for approximately 30 years, while the majority of Caucasian cardiologists might have been little interested in the existence of coronary artery spasm.
Complications Serious major complications including death were reported by the intravenous injection of ER [47], [48]. However, no irreversible complications were observed by the intracoronary administration of ER. Selective ER test is safer than the intravenous injection of ER. Considering the occurrence of refractory spasm induced by ER, we recommend the selective spasm provocation test instead of unselective test. In our 1114 ER experiences, we had four major complications including two ventricular fibrillations and two ventricular tachycardias, which required direct current to recover sinus rhythm in two patients. However, no irreversible complications were recognized in our experiences. In contrast, Ong et al. reported that the complication rate of intracoronary ACh test was low. However, we experienced 28 major complications [1.8% (28/1546)] when performing intracoronary ACh tests. We administered the ACh into the responsible vessels for 20–30s, whereas Ong et al. administered the ACh into the responsible vessels over 3min without temporary pacemaker insertion. We routinely inserted the temporary pacemaker in all ACh tests. Moreover, we performed ACh spasm provocation tests on both coronary arteries in almost all patients, whereas Ong et al. performed ACh tests on both coronary arteries in only a third of the patients. Recently, Isogai et al. reported that the ACh spasm provocation tests were associated with a higher rate of serious cardiac complications than the ER tests from the analysis of 21512 patients in the diagnosis procedure combination database in Japan [0.9% (96/10628) vs. 0.4% (45/10884), p<0.001] [49]. Serious major complications during ACh tests were higher than those of ER tests, but not significantly in our experience [0.9% (14/1546) vs. 0.4% (4/1114), ns], because our sample size was small. However, we had no irreversible complications during ACh and ER spasm provocation tests [50].