Electrocardiographic manifestations of hypothermia and the 'J (Osborn) wave'

Background

Hypothermia is defined as a core temperature less than 35°C. Critical trauma patients usually are hypothermic. A reversible coma simulating cerebral death could be one of the clinical manifestations of hypothermia. Life-threatening ventricular arrhythmias could be evident when moving the patient and during the rewarming process. Electrocardiographic manifestations of hypothermia are: bradycardia, absence of atrial activity, narrow QRS complexes and a prolonged QT interval. The presence of the 'J (Osborn) wave', a second upward wave immediately following S waves, is pathognomonic. The 'J (Osborn) wave' is the result of the difference of potential action between the epicarde and endocarde during phases 1 and 2 of the ventricular repolarisation and is related to increase in mortality.

Objective

To report a case of penetrating thoracic gunshot wound with electrocardiographic manifestations of hypothermia, including a 'J (Osborn) wave', who died.

Methods

Case report and literature review.

Results

A 30-year-old male injured in the left hemithorax was transferred to our emergency department 8 hours after aggressive initial resuscitative thoracotomy, total left pneumectomy and cardiopulmonary maneuvers. He was admitted in shock, midriasis and with core temperature of 32°C, after 1.5 hours of interhospital transportation. A ventricular fibrillation occurred and was treated with two biphasic shocks. An electrocardiogram showed: an absence of P waves, a ventricular rate of 78 beats, narrow QRS complexes, a prolonged QT interval and a 'J (Osborn) wave' (Figure 1). The patient was resuscitated by the principles of early goal direct therapy and was submitted to external and internal rewarming processes. Although there was an effective and clear diuresis, an improvement in lactic acidosis and central venous saturation, and a body temperature of 36°C, the patient had cerebral death declared on the second day and died on the third day.

Figure 1

Electrocardiographic manifestations of Hypothermia: absence of P waves, ventricular rate of 78 beats, narrow QRS complexes, a prolonged QT interval and the 'J (Osborn) wave' (white arrows).

Conclusion

The search for electrocardiographic manifestations of hypothermia should be part of the routine for critical trauma patients and, when reported, should alert the surgical team about the possibility of supporting a bad prognosis.