title: Syndrome X: diagnostic criteria and long term prognosis.
abstract: Patients with syndrome X have an appreciable reduction in coronary reserve, i.e. the dilatory capacity of the coronary resistance vessels. Whereas the intramyocardial vessels are normal, there are degenerative changes in myocardial cells, shown on electron microscopy. Left ventricular function is normal under resting conditions but becomes abnormal during isometric or dynamic stress. The diagnosis of syndrome X is predominantly based on a marked reduction in coronary reserve. Furthermore, delayed T1-wash out and increased glutamate turnover have been observed. Follow-up studies reveal some heterogeneity of patients studied; in patients with syndrome X and left bundle branch block left ventricular function deteriorates progressively.
mesh_terms: D000787:Angina Pectoris / Q000175:diagnosis* / Q000503:physiopathology; D003326:Coronary Circulation; D003331:Coronary Vessels / Q000503:physiopathology; D006439:Hemodynamics; D006801:Humans; D011379:Prognosis; D013577:Syndrome; D013997:Time Factors