Exercise-induced myocardial ischemia in isolated coronary artery ectasias and aneurysms ("dilated coronopathy").

OBJECTIVES: The purpose of our study was to evaluate the clinical significance of isolated coronary artery ectasias or aneurysms (CEA).

BACKGROUND: It has been postulated that altered coronary blood flow in CEA predisposes patients to the development of myocardial ischemia (CI) and infarction.

METHODS: Sixty-seven patients with bilateral nonobstructive CEA without associated cardiac defects ("dilated coronaropathy") were derived from 16,341 cardiac catheterizations between 1986 and 1997. Ectasias were defined as luminal dilation of 1.5- to 2.0-fold, aneurysms of >2.0-fold of normal limits. Eleven of 25 patients presented with myocardial infarction due to an occlusion of the infarct vessel. In 42 patients without infarction (study group), exercise-induced CI was investigated.

RESULTS: A corresponding CI was documented in 32 of 42 patients in a coronary sinus lactate study (reduced lactate extraction 5.6 +/- 4.1%) and in 29 of 40 patients in an ergometry (0.25 +/- 0.06 mV ST depressions). The results differed significantly from a control group of 29 patients without heart disease (p < 0.001). Nitroglycerin (0.8 mg) provoked a further significant deterioration of CI in the 32 of 42 developing a frank cardiac lactate production (-2.6 +/- 6.8%, p < 0.001). The metabolic extent of CI was significantly correlated to the coronary diameters of the proximal and middle segments of left anterior descending artery and the middle segment of left circumflex artery (r = 0.87, p < 0.001). Stigmata of an impaired coronary blood flow such as delayed antegrade filling, segmental backflow phenomenon and local deposition of dye were found significantly more often with increasing coronary diameters (p < 0.04).

CONCLUSIONS: "Dilated coronaropathy" is an entity of nonobstructive, ischemic coronary artery disease. Nitroglycerin is of no therapeutic benefit but leads to an aggravation of exercise-induced CI.