The effect of lethal electrical shock on postmortem serum myoglobin concentrations

Postmortem serum myoglobin concentrations in blood from the femoral vein (peripheral withdrawal) and the heart (central withdrawal) of nine electrical fatalities were compared with those of 74 individuals who had died of other causes. Independent of the cause of death or topographical site, serum myoglobin concentrations rose dramatically with the passage of postmortem time (maximum concentrations in the control group: 975,100 micrograms/l). In 59% of the total sample (electrical fatalities plus controls), serum myoglobin concentrations were higher in the central blood, in the other 41% the concentrations were higher in the peripheral blood. The differences in concentrations between the peripheral and the central withdrawal area correlated with neither the postmortem interval nor the cause of death. Up to the second day postmortem there was a statistically significant difference in serum myoglobin concentrations between electrical fatalities and controls. The individual values within each group, however, varied widely and overlapped between groups. Controls who had also suffered muscle injury (polytrauma, myocardial infarction) did not have significantly higher serum myoglobin concentrations than controls without muscle injury. Myoglobin concentrations appear to be greatly influenced by the extent and duration of the muscle cramps induced by the electrical current. Correct interpretation of serum myoglobin concentrations depends on the knowledge of events surrounding the lethal electrical shock. Postmortem determination of serum myoglobin concentrations alone is, therefore, not sufficient to establish intravital exposure to electrical current and can aid the diagnosis only in special cases.