[Electrocardiographic changes in accidental hypothermia]

Abstract

Purpose: Electrocardiographic alterations were evaluated in a group of accidental hypothermia patients, and correlated with values of core temperature, pH and plasmatic concentrations of Na+, K+ and Cl-.

Methods: Conventional 12-lead surface electrocardiograms were obtained in a group of 32 patients with accidental hypothermia after involuntary cold exposure. Cardiac arrhythmias, QRS configuration, ST-T segment and T wave alterations were analyzed. pH, Na+, K+ and Cl- serum concentrations were simultaneously measured. Electrocardiogram and electrolyte abnormalities were then correlated with the core temperature.

Results: Twenty-eight patients had abnormal electrocardiogram (90.6%). Sinus bradycardia and idioventricular rhythm were observed in 11 and 3 patients respectively. QT interval enlargement was found in 24 patients and Osborn wave in 28 cases. Altered T waves expressing an abnormal repolarization were observed in 23 cases. A significant negative correlation was obtained when J wave amplitude was correlated with core temperature levels.

Conclusion: Hypothermia produces electrocardiographic abnormalities characterized by Osborn waves. Other minor findings include sinus bradycardia, idioventricular rhythm and long QT intervals.