The effect of aminophylline infusion on the exercise capacity in patients with syndrome X.

Aminophylline was known to decrease effort angina and ischaemia in patients with coronary artery disease and stable angina. This effect has been explained by the antagonization of the vasodilatation caused by adenosine and the prevention of the transmural myocardial maldistribution (steal phenomenon). In this study, treadmill exercise tests (with Bruce protocol) were performed in 14 patients (11 women, 3 men, mean age 51 +/- 9.9 years) diagnosed with syndrome X (typical anginal chest pain, abnormal stress test, normal coronary angiography) before (basal condition) and after the acute i.v. aminophylline infusion (total dosage 6 mg/kg within 15 minutes). It was shown that aminophylline lengthened the time before the occurrence of ischaemia in patients with syndrome X by increasing the ischaemia threshold in spite of the occurrence of tachycardia but it had no effect on the total exercise duration. Aminophylline infusion also exerted a beneficial effect on exercise-induced chest pain. It has been suggested that the role of the adenosine receptor could be important in the pathogenesis of syndrome X.

Interferons: their role in clinical practice.

OBJECTIVE: To describe the current indications and side effects of Interferons in the treatment of human disease together with sufficient background information to understand the rationale for their use. DATA SOURCES: Literature searches on interferons extended back to the time of their discovery. Citations were limited to English and human aspects. Reference lists from recent reviews were also consulted. STUDY SELECTION: Reviews of fundamental mechanisms were selected together with studies of individual clinical trials and anecdotal experiences with human use of interferons. CONCLUSIONS: Interferons are accepted therapy for a number of conditions. Their range of therapeutic uses will undoubtedly increase as further knowledge is obtained.