Osborn waves due to severe hypothermia

A 60-year-old woman, known for illicit drug use and treated for severe depression was found unconscious at her home with a body temperature 24.5 °C due to intoxication of opiates and multiple psychotropic drugs (flurazepam, citalopram, levomepromazinum, clonazepam). An electrocardiogram (ECG) was obtained at her admission showing large J waves (or Osborn waves) in the 12 leads, with sinus bradycardia at a rate at 48/min and a prolongation of the PR, QRS and QT intervals (fig. 1). She was intubated due to hypoventilation and active rewarming measures were initiated, which consisted of administration of warmed intravenous saline, heated humidified oxygen and use of a warming blanket. Four hours after admission her body temperature had risen to 29° C and a repeat ECG showed a slight regression of the abnormalities (fig. 2). The last ECG, done when the hypothermia was corrected, showed disappearance of the J waves, normalisation of the QRS and QT intervals and acceleration of the sinus rate to 111 beats/min (fig. 3). The patient made full neurological recovery.