Changes in the fetal ECG pattern, specifically ST-T changes and bradycardia, correlate strongly with myocardial glycolysis and early hypoxic stress in a guinea pig model.
The depletion of glycogen, creatine phosphate and ATP in the fetal heart, liver and brain was studied in 40 mature guinea pig fetuses acutely exteriorized and submitted to a graded hypoxia. A strong linear correlation was found between an ECG scoring system, taking the severity of the ST-T changes into account, and the depletion of heart glycogen and creatine-P. ATP was unaffected until glycogen was almost depleted (25 % of initial value). At this point, brain and liver glycogen were also severely affected. Bradycardia (AV-block, type II) was strongly correlated to failing myocardial metabolism. It is concluded that the changes in the fetal ECG pattern could be regarded as a sign of myocardial glycolysis and early hypoxic stress.
Rosén et al. (2009) studied this question.