The Administration of Oxytocin or Carbetocin at the Time of Cesarean Section Is Not Associated with Changes in the Electrocardiogram.

Oxytocin as well as carbetocin, a synthetic analog of oxytocin with a longer duration of action, can affect the cardiovascular system, which can be recorded in electrocardiographic Holter recordings. The choice of the appropriate dose of oxytocin or carbetocin should take into account potential cardiovascular effects. A total of 70 pregnant women who previously qualified for elective cesarean section and enrolled in the study were divided into two groups. The oxytocin group (OXY) received 5 IU of oxytocin intravenously (i.v.). The carbetocin group (CARBE) received 100 µg of carbetocin intravenously. Both drugs were used alternatively to contract the uterine muscle. Continuous Holter electrocardiograph recording started 30 min before the procedure and continued until about 3 h after the procedure. No abnormalities were observed in either of the analyzed groups during intraoperative ECG recordings at either the highest or lowest recorded heart rate values. The incidence of ST-segment-lowering episodes, the depth of the denivelation and its duration did not differ between the groups studied. The incidence of additional ventricular beats was comparable in the OXY and CARBE groups, both before and after the administration of uterotonic drugs. In the CARBE group, no significant changes in MAP were recorded during the entire ST-segment-lowering period. Analysis of heart rate changes during ST lowering showed no differences between the study groups. A thorough analysis of perioperative ECG recordings revealed no significant alterations in ECG patterns, neither in response to oxytocin nor carbetocin administration during cesarean sections.