Hypothermia is a medical emergency that occurs when your body loses heat faster than it can produce it, causing a dangerously low body temperature.
Occurs when body temperature falls below 35 °C.
Left untreated, hypothermia can lead to complete failure of the cardiovascular and respiratory system and eventually to death.
Mild hypothermia is 32-35 °C
Moderate hypothermia is 29-32 °C
Severe hypothermia is < 29 °C
Clinical presentation
excessive shivering, weak pulse, slowed breathing, slowed speech, clumsiness or lack of coordination, confusion or memory loss
ECG manifestation
shivering artefact
bradyarrhythmia
prolonged PR interval, QRS and QT interval
Osborn waves (J waves) - a positive deflection at the J point (negative in aVR and V1), most prominent in inferior and precordial leads; the height is roughly proportional to the degree of hypothermia
ectopic activity -> atrial fibrillation
If temperature below 30°C
ventricular fibrillation
If temperature below 28°C
cardiac arrest due to VT, VF or asystole
Picture 1 Osborn wave
ECG 1A Patient after CPR before targeted temperature management (only atrial fibrillation present)
ECG 1B Patient during targeted temperature management (34° C) - slower rate of atrial fibrillation, ST elevations with incipient Osborn waves (II, III, aVF, V5-V6), prolonged QT interval.
