Myocardial ischaemia in normal patients undergoing elective Caesarean section: a peripartum assessment

Abstract

SummaryIncidence rates of electrocardiographic changes during Caesarean section vary from 25 to 60%. To date, no investigator has identified myocardial ischaemia resulting from these changes. We investigated patients undergoing elective Caesarean section using peripartum Holter monitoring and serum analysis of cardiac troponin I (cTnI). Twenty-six patients presenting for elective Caesarean section were studied. Peroperative Holter monitoring continued for 12 h postoperatively, at which time blood samples for cTnI levels were taken. Significant ST changes were recorded in 42% of patients peroperatively and 38.5% of patients postoperatively. Forty-two per cent of patients experienced peroperative chest pain requiring opioid analgesia. Chest pain was significantly associated with abnormal electrocardiogram (ECG) findings. Ischaemic levels of cTnI were recorded in two patients. This study reports, for the first time, myocardial ischaemia (7.69% of patients) arising in conjunction with the ECG changes seen during elective Caesarean section. We also report episodes of significant postoperative ST-segment changes.

ST depression at caesarean section and the relation to oxytocin dose. A randomised controlled trial

“…In spite of the fact that the participants were healthy, a few subjects had elevated Troponin I levels indicating myocardial damage. This finding is in agreement with the study by Moran et al, 4 and although there might be false positive values, the finding is difficult to ignore.…”

“…[1][2][3] In previous studies, most of the ST depressions have occurred after delivery, which is the time period, when oxytocics are given. 1,2,4 Oxytocin as a causative agent has not been discussed in detail in previous studies and is sometimes not mentioned at all. 2,3 The association between ST depression and oxytocin administration is in agreement with the results by Svanstrom et al, 5 who in a double blind, randomised controlled trial studied effects of oxytocin bolus on ECG in comparison with methylergometrine, in patients undergoing elective CS under spinal anaesthesia.…”

“…1,4 Subjects with symptoms and concomitant ST depression were only found in the 10 unit group, in one of whom myocardial-cell injury was confirmed (elevated Troponin I level). In spite of the fact that the participants were healthy, a few subjects had elevated Troponin I levels indicating myocardial damage.…”

“…28 Overall, symptoms were much less frequent compared with frequencies reported in previous studies. 1,4 Palmer et al 1 reported all complaints and, in the study by Moran et al, 4 patients were asked for symptoms per-operatively, which could explain differences besides the differences in doses and in the way the drug was administered. The incidence of symptoms is known to be lower when the investigator waits for spontaneous complaints and thus, the incidence may have been underestimated in our study.…”

“…[1][2][3][4] An association with oxytocin administration has recently been described in a randomised trial using 10 units of oxytocin. 5 Oxytocin, given as an intravenous bolus, causes transient hypotension, a reflex tachycardia and an increase in cardiac output, in healthy women undergoing caesarean section under spinal anaesthesia.…”