[Induced coronary spasm: immediate revascularization by the opposite coronary artery. Use of myocardial scintigraphy]. / Spasme coronaire provoqué revascularisation immédiate par suppléance hétérocoronarienne. Apport de la scintigraphie myocardique.

The case reported analyses the instantaneous revascularisation distal to a coronary spasm by electrocardiography and thallium scintigraphy. The patient, a 48 year old man, had an 18 months history of spontaneous anginal chest pain sensitive to trinitrin. No electrocardiogrammes had been recorded during an attack. Coronary angiography was normal apart from a slight reduction in calibre of a dominant right coronary artery. Injection of 0.4 mg methylergometrine provoked an occlusive spasm of this artery after 4 minutes. At the same time the patient experienced angina and 4,5 mm depression of the ST segment, without ST changes in D3 and AVF, was observed. Opacification of the left coronary artery during spasme of the right showed retrograde revascularisation of the posterior interventricular artery which was reversed when the coronary spasm was terminated with trinitrin. Thallium scintigraphy was performed during another spasm provocation test four days later which gave identical clinical and electrical changes. A zone of hypofixation with blurred limits over the inferior myocardial wall was demonstrated. In the absence of ST elevation and of lacuna on myocardial scanning, the myocardial ischaemia induced by this occlusive spasm could not be considered to be total. Therefore the immediate revascularisation of the coronary artery in spasm seemed to have played the role of an effective collateral circulation.