Fig. 4.

A representative case with MB and SPT-negativity in the LAD but with SPT-positivity in the RCA on the coronary angiogram before (a–c) and after the SPT (c, f). Before the ER injections, the LCA angiogram shows no significant stenosis during end-diastole (a) but MB in the mid-LAD is observed as shown by the “squeezing” (arrow heads) (b). After the ER injections into the LCA, the LAD does not have any spastic changes (c). Before the ER injection in the RCA, no stenosis was observed (e), but the ER injections cause a subtotal occlusion (f). In this case, the culprit vessel of the SPT-positivity was the RCA. CAG coronary angiography, SPT spasm provocation test, ER ergonovine, LCA left coronary artery, LAD left anterior descending coronary artery, RCA right coronary artery