[False failure of an aortocoronary bypass. Spasm of an artery revascularized by 2 saphenous vein graft].

The cause of recurrent resting angina one year after aorto-coronary bypass is presented. A 65 year old female with effort and resting angina with syncope had an isolated narrowing of the proximal portion of the left anterior descending artery on coronary angiography. Saphenous vein aorto-coronary bypass and cardiac plexectomy were performed on the 18 . 12 . 78, and an excellent result was obtained in the first postoperative year. Nocturnal angina with syncope recurred on the 31 . 12 . 79 and anterior subendo-cardial ischaemic changes were noted on the post critical electrocardiogramme. On control angiography 10 days later, the bypass graft was shown to be patent. A provocative test with methylergometrine showed spasm of the whole of the revascularised artery without any changes in the other vessels. Attacks of spontaneous angina with ST depression on Holter monitoring continued despite treatment with Nifedipine (6 capsules/day). The substitution of Diltiazem (3 capsules/day) prevented further recurrence with a follow-up of three months. The authors conclude that spontaneous angina after aorto-coronary bypass is not synonymous with graft dysfunction, and suggest that the effects of cardiac denervation in vasospastic angina, where Nifedipine and Diltiazem seem to have different modes of action, need further confirmation.