Complaints of chest symptoms including pressure, tightness, or pain frequently occur during cesarean delivery under regional anesthesia. The aim of this study was to test whether methergine (methylergonovine maleate) aggravates chest symptoms and/or ECG changes during cesarean section under spinal anesthesia, and to determine if these changes are associated with any discernable intraoperative event.

After delivery, patients were given intravenous methergine 0.2 mg and diluted oxytocin 10 i.u. in 1000 ml Ringer's lactate solution (Methergine group, n = 30) or diluted oxytocin 20 i.u. (Control group, n = 29). ECG and hemodynamic responses were monitored continuously on 12 leads perioperatively.

Methergine significantly increased the incidence of chest symptoms compared to the control group (30% vs. 3.4%, P < 0.05), but this increase was not correlated with ECG ST segment changes or with other intraoperative events. ECG changes suggestive of myocardial ischemia occurred in the two groups to similar extents (34.5% vs. 30%, P > 0.05).

Methergine-induced chest symptoms per se do not signify evident myocardial ischemia during cesarean delivery. However, anesthesiologists must not overlook the possibility of a small coronary arteriolar spasm, especially in high-risk patients.