Table 5.

SPT-positivity rate and prevalence of MB compared with the previous reports

	Definition of MB	Definition of SPT-positivity	SPT-positivity rate			Provocation drugs	Prevalence of MB (%)
			All (%)	MB (+) group (%)	MB (−) group (%)
Arai et al	Angiographic reduction in the diameter of the coronary artery during systole, also known as the “milking effect” between systole and diastole	Total or subtotal occlusion with ECG changes and/or chest pain	27.1	56.5	22.4	ER	13.9
Teragawa et al. [8]	Angiographic reduction in the diameter of the coronary artery during systole of > 15%	≥ 50% reduction in the arterial diameter, associated with ECG changes and/or chest pain	51.8	73.2	39.7	ACH and ER	36.0
Saito et al. [12]	Angiographic systolic narrowing of coronary vessels that was pronounced than in neighboring normal vessels, with partial or complete decompression during diastole (i.e. milking effect)	Total or subtotal occlusion with ECG changes and/or chest pain	49.0	59.3	43.3	ACH	35.7
Xiang et al. [19]	50% angiographic reduction in the diameter of the coronary artery during systole	90% or above reduction in the arterial diameter with ECG changes and/or chest pain	63.4	85.3	53.4	ACH	31.5

SPT spasm provocation test, MB myocardial bridging, ECG electrocardiogram, ER ergonovine, ACH acetylcholine