[Comparison of the oxygen deficit and ischemia pain threshold in patients with silent and symptomatic myocardial exercise-induced ischemia]

Abstract

In 39 patients with angiographically documented coronary artery disease and silent or symptomatic myocardial ischemia under exertion it was investigated if there is a difference in forearm skeletal muscle ischemia and ischemic pain threshold. The degree of myocardial ischemia was determined by plethysmographically measured reactive hyperemia. In 12 asymptomatic and eight symptomatic patients maximal reactive hyperemia was induced by ischemic work in the forearm skeletal muscle. After termination of ischemia there was a significantly higher reactive hyperemia at 20, 90, and 180 s in the asymptomatic patients. Furthermore, nine asymptomatic and 10 symptomatic patients underwent symptom-limited ischemic work until weakness or pain developed. Under these conditions reactive hyperemia as a parameter of oxygen deficiency was higher in the asymptomatic patients. The difference was not statistically significant. There was, however, a significantly higher incidence of ischemic pain in the symptomatic patients. It can be concluded that patients with asymptomatic myocardial ischemia tolerate a higher oxygen deficit in the working forearm and have a higher pain threshold than patients with symptomatic ischemia.