Incidence of electrocardiographic changes indicating myocardial ischemia during cesarean sections under spinal anesthesia

Objective: Electrocardiographic (ECG) changes and chest symptoms suggestive of myocardial ischemia have been reported in healthy women during cesarean section under regional anesthesia. This study aimed to determine the incidence of ECG changes and find any relation between the changes and subjective chest symptoms, hemodynamic variables, oxytocin, and ephedrine administration. Materials and Methods: ECG changes were recorded in 237 term parturients during elective cesarean section done under spinal anesthesia. ST-T depression of ≥1 mm and elevation of ≥2 mm for at least 1-min were considered as significant. Timing of hypotension, bradycardia, tachycardia, ECG changes, and chest symptoms were recorded. Pearson correlation coefficient was used to determine the association between ST changes and subjective chest symptoms, hemodynamic variables, oxytocin, or ephedrine administration. Results: Of 237 patients, 71 (30%) had significant ST-T depression, and 83 (35%) complained of chest symptoms (pressure, squeezing, pain, or dyspnea). Of 71, 42 had chest symptoms. Chest symptoms were also experienced by 30 (18%) patients where no change in ECG was seen (166/237). The changes were more commonly noted at delivery or 3-10 min after oxytocin administration. No correlation was found between ECG changes and chest symptoms, hemodynamic variables, and ephedrine, but there was moderate positive relation with oxytocin. Conclusion: Chest symptoms and ECG changes consistent with myocardial ischemia were observed in about 1/3 healthy parturients during cesarean section. An association between oxytocin and ECG changes was found in half of the patients. The symptoms were short lived and required no treatment.