[X syndrome: does left ventricular myocardial perfusion suffer during exercise?].

Sixteen patients with the X syndrome underwent thallium-201 myocardial scintigraphy. Eleven patients with one-coronary artery disease served as a control group. During bicycle ergometry all the 16 patients showed various degrees of local myocardial perfusion impairments. The foci were located in the basins of various coronary vessels. Impaired myocardial perfusion in patients with the X syndrome was similar to that in patients with moderate, but hemodynamically significant stenosis of a coronary artery. At the same time the impairments were significantly less pronounced than in those with critical stenosis of a coronary artery. Thus, patients with the X syndrome have not only clinical signs of coronary heart disease (anginal episodes), but they also have marked myocardial perfusion impairments during exercise.