[Changes in plasma endothelin during coronary spasm].

The role of endothelin, a powerful vasoconstrictor, was studied in coronary spasm. A methylergonovine stress test was performed in patients with normal coronary angiography. Patients who developed spasm (Group I, n = 6) were compared with those who did not (Group II, n = 6). Plasma endothelin was measured at 8, 11 a.m., 2 p.m., 4, 7, 9, 11 p.m. and 1 a.m. The stress test was carried out at 17 hours and an additional endothelin measurement was performed during spasm in positive cases. The clinical characteristics of the two groups were comparable especially with regards to cardiovascular risk factors. Except for the value recorded during coronary spasm, the plasma endothelin levels were significantly higher in the group with coronary spasm. A time-dependent variation was observed in both groups with higher endothelin levels in the morning. In group I the plasma endothelin levels were higher under basal conditions and during spasm in patients with spastic angina.