CM&R 2008: 3/4 (December)108 Classic EKG Changes of Hypothermia

lidocaine, and citalopram. She was extubated in less than 24 hours and was discharged from hospital in 3 days. The incident was thought to be an attempted suicide, which resulted in her exposure to cold weather conditions for 24 hours. J waves (also called Osborne waves) are pathognomonic for hypothermia when present.1 These look like “delta ” or “camel’s hump ” waves after regular QRS complex.1 J waves or Osborne waves appear secondary to an exaggerated outward potassium current leading to repolarization abnormality.2 These waves are detectable in 80 % of the patients when core body temperature is lower than 30°C.3 J waves are seen in lead II and precordial leads V2-V6.1 Similar findings can be seen in patients with hypercalcemia, Brugada syndrome, and early repolarization.1 Our patient had significant hypokalemia and it could have contributed to the prolonged QRS. It should be noted, however, that the plasma potassium levels do not generally correspond to the electrocardiographic changes of hypokalemia.4 J waves are not prognostic indicators when they are present, unlike atrial fibrillation, which incurs survival disadvantage.5 Fatal ventricular fibrillation or asystole can occur when core body temperature is below 28°C.