The Conundrum of Cardiovascular Syndrome X.
Patients found to have normal or near-normal coronary angiograms at the time of cardiac catheterization often continue to have chest pain symptoms despite reassurances of a benign prognosis. Many groups have investigated the possibility of a dynamic abnormality in coronary flow responsiveness to stress, but with conflicting results. Furthermore, objective metabolic and hemodynamic evidence of myocardial ischemia during stress generally has been absent, even in those patients selected for an ischemic-appearing ST segment response to exercise (often designated as syndrome X). In recent years, several groups have noted an abnormal pain sensitivity during the performance of cardiac catheterization and during dobutamine infusion. Use of therapies effective in chronic pain syndrome management may be of symptom benefit to many.
Cannon
RO
National Institutes of Health, Bethesda, Maryland.