Iatrogenic Giant Osborn Waves
A 57-year-old man was admitted after an out-of-hospital cardiac arrest. He received bystander basic life support followed by prolonged resuscitation at the emergency department and was subsequently transferred to the intensive care unit under mechanical ventilation. Therapeutic cooling was introduced, and his core temperature was monitored with a rectal thermometer. As a result of false high temperature readings secondary to sensor malfunction, cooling procedures were intensified and severe ECG changes appeared on the cardiac monitor. The rectal thermometer was replaced, and a core temperature of 27°C was recorded. ECG demonstrated giant Osborn waves that progressively diminished once rewarming was initiated (Figure).
Osborn or J wave is a common ECG finding in hypothermia, appearing as a slow upright deflection between the end of the QRS complex and the early portion of the ST segment. Hypercalcemia, vasospastic angina, Brugada syndrome, and subarachnoid hemorrhage can demonstrate a similar ECG pattern.
- © 2010 American Heart Association, Inc.