[Assessment of plasma catecholamine and beta-endorphin contents in patients with silent myocardial ischemia and angina pectoris].

Thirteen patients with totally silent myocardial ischemia (group 1) and 15 patients with effort angina (group 2) were studied. The coronary angiography of both groups indicated coronary artery stenosis > or = 50%. In group 1, the beta-endorphin plasma level (beta-EPL) during rest was significantly higher than those in group 2 (15.639 +/- 1.258 pg/ml and 8.920 +/- 1.478 pg/ml, respectively, P < 0.01). There were significant increases in beta-EPL in both groups after exercise as compared with that before exercise (beta-EPL is 33.801 +/- 6.243 pg ml/in group 1, P < 0.01; 18.169 +/- 3.540 pg/ml in group 2, P < 0.01). The difference between two groups after exercise was also significant (P < 0.05). The plasma level of noradrenaline (NE) during rest was 0.267 +/- 0.035 ng/ml, adrenaline (E) was 0.112 +/- 0.018 ng/ml in group 1, and NE was 0.218 +/- 0.032 ng/ml and E was 0.110 +/- 0.015 ng/ml in group 2. After exercise, NE was 1.017 +/- 0.160 ng/ml (P < 0.001), E 0.276 +/- 0.076 ng/ml (P < 0.001), E 0.260 +/- 0.043 ng/ml (P < 0.01) in group 2. There was no difference between two groups both in rest and after exercise (P > 0.05). This study indicates that the high plasma beta-endorphin level might play a major role in the occurrence of totally silent myocardial ischemia.