Postmortem increase of flecainide level in cardiac blood

We encountered a case of fatal congestive heart failure that occurred under the influence of flecainide. In this case, an extreme postmortem increase in the flecainide level was identified in cardiac blood. The patient had been administered 400 mg/day of flecainide for seven days before death. Antemortem plasma obtained 13 h before death showed a flecainide concentration of 2.5 mg/L and a pH of 7.4. In comparison, centrifuged supernatants of postmortem right and left cardiac blood contained flecainide concentrations of 13.8 and 44.2 mg/L, respectively, with pH of 5.5 in both samples. This increase in blood flecainide concentration was attributed to postmortem redistribution, as about 18 h had passed between the last intake of flecainide and death.