ACh (n=1546) ER (n=1114) Adding ACh after ER test (n=240)                 Serious major complications 14 (0.9%) 4 (0.4%) 0   VF 4 2 0   Sustained VT 1 0 0   Shock (like left main trunk spasm) 6 0 0   Hypotension (severe <60 mmHg) 2 0 0   Cardiac arrest 0 2 0   Cardiac tamponade 1 0 0         Major complications 28 (1.8%)** 4 (0.4%) 0   VF 4 [2] 2 0   VT 20 [4] 0 0   Shock (like left main trunk spasm) 6 0 0   Hypotension (severe < 60 mmHg) 9 (6) 0 0   Cardiac arrest 0 2 0   Cardiac tamponade 1 0 0         Minor complications         Paroxysmal atrial fibrillation 258 (16.7%) 0 30 (12.5%)         Other complications         Reciprocal ST elevation 19 (1.2%)* 3 (0.3%) 0

(ACh: acetylcholine, ER: ergonovine, VF: ventricular fibrillation, VT: ventricular tachycardia, susVT: sustained VT, [ ]: include hypotension, ( ): include shock, *p<0.05, **p<0.01, vs. ER)

Table 1: Serious major, major and minor complications among three spasm provocation tests.