[Detection of stress-induced myocardial ischemia in isolated coronary ectasia and aneurysm (dilatative coronaropathy)].

Forty eight patients with bilateral isolated non-stenotic coronary artery ectasia or aneurysm without associated cardiac defects ("dilated coronaropathy") were identified in consecutive diagnostic cardiac catheterizations between 1986-6/1994 (angiographic incidence 0.44%). Ectasia was defined as a luminal dilatation of the 1.5-2-fold, aneurysm of more than double the normal limits. In 16 patients a myocardial infarction (5 non-q-infarctions/11 q-wave-infarctions) was the indication for coronary angiography, a thrombotic occlusion of the infarct vessel was documented in 8/16 patients. In patients without myocardial infarction (study group) an evaluation of exercise-induced myocardial ischemia was performed by means of a coronary sinus lactate study, treadmill ergometry and Thallium-201-scintigraphy. A corresponding coronary insufficiency was objective in all tests in the study group. An exercise-induced myocardial ischemia was found in 21/31 in the coronary sinus study, 19/29 in the treadmill ergometry and 13/26 patients in the scintigraphy; significant differences were found in comparison to the results of a control group of patients without heart disease (n = 29, p < 0.001). After administration of 0.8 mg nitroglycerin (NTG) a further significant deterioration of myocardial ischemia was measured in the 21 patients with pathologic lactate metabolism developing a frank cardiac lactate production (p < 0.03). The extent of myocardial ischemia in the coronary sinus study was significantly correlated to the coronary diameters of the proximal and middle segments of the Ramus interventricularis anterior and the middle segment of the Ramus circumflexus (r = 0.87, p < 0.02). A differentiation between ectasia and aneurysm therefore seems to be of functional relevance. Angiographic stigmata of an impaired coronary blood flow such as a segmental to and from movement and a local deposition of dye were found significantly more often with increasing coronary diameters (p < 0.04). "Dilated coronaropathy" is an entity of non-stenotic, ischemic coronary artery disease. NTG was of no therapeutic benefit or led to an aggravation of the exercise-induced myocardial ischemia. Because of this potential adverse effect the administration of NTG should be avoided in "dilated coronaropathy".