084 - Electrocardiogram ST-segment morphology and cardiac troponin T in severely asphyxiated piglets

Kathrine S. Hansen, Oslo University Hospital, University of Oslo, Tårnåsen, Akershus, Norway; Eydis Oddsdottir. Stenersen, University of Oslo, Oslo, Oslo, Norway; Arild Rønnestad, University of Oslo, Oslo, Oslo, Norway; Anne Lee Solevåg, Oslo University Hospital, Oslo, Oslo, Norway

Background: Cardiac involvement is frequently observed in perinatal asphyxia.

Objective: This study aimed to generate hypotheses about whether electrocardiogram (ECG) ST-segment morphology alone or in combination with high-sensitivity cardiac troponin T (cTnT-hs) could serve as diagnostic and prognostic markers in severe cases of perinatal asphyxia.

Design/Methods: Anaesthetized and mechanically ventilated neonatal piglets were asphyxiated until cardiac arrest, resuscitated and observed for 4 h after return of spontaneous circulation (ROSC) with continuous one-lead ECG and arterial blood pressure. The ECG ST-segment was analyzed at baseline, 15 min of asphyxia, 15 min, 2h and 4h after ROSC, and categorized as “Normal”; “ST-elevation; “ST-depression” or “Other ST-changes”. cTnT-hs was analyzed at baseline, and 2h and 4h after ROSC. ECG ST-segment morphology and cTnT-hs, and their association with cardiovascular- and blood gas variables, duration of asphyxia, time to ROSC and survival were analyzed.

Results: Fifty piglets with ECG and/or cTnT-hs were included. Four piglets did not achieve ROSC, and five piglets did not survive the whole experiment. ECG of sufficient quality was obtained at baseline (n=17), 15 min of asphyxia (n=21), and 15 min (n=12), 2 h (n=9) and 4 h after ROSC (n=13). ST-elevation was most common at all timepoints (94%, 71%, 67%, 89% and 77%, respectively). ST-depression (n=1) and other ST-changes (n=3) were only present during or after asphyxia. cTnT increased time-dependently after asphyxia. There was no association between ST-segment changes and cTnT-hs. cTnT-hs correlated negatively with pH 2 h (rs=-0.321, p=0.034), and pH 4 h (rs=-0.419, p=0.008) after ROSC. There was a positive correlation between cTnT-hs and lactate 4 h after ROSC (rs=0.383, p=0.015). cTnT-hs 4 h after ROSC and time to ROSC (rs=0.348, p=0.026), and time with cardiac compressions (rs=0.323, p=0.040) correlated. ST-segment morphology or cTnT-hs, and survival were not associated.

Conclusion(s): ST-elevations were the most common findings, while ST-depression and other ST-changes only occurred during or after asphyxia. cTnT-hs levels increased time-dependently after asphyxia but did not provide additional information beyond that of arterial pH and lactate. High incidence of ST-elevations before asphyxia may indicate that ST-segment morphology is a poor diagnostic and prognostic marker in severe perinatal asphyxia. Thus, future clinical studies on one-lead ECG should examine other components of the ECG.