The Osborn wave, also known as a J wave, appears as a positive deflection at the J point in ECG leads. It is most commonly associated with hypothermia below 30 degrees Celsius. Other potential causes include hypercalcemia, myocardial ischemia, Takotsubo cardiomyopathy, hypertension, early repolarization, neurological insults, myocarditis, and genetic conditions. The height of the J wave tends to increase with greater severity of hypothermia. Osborn waves are a specific sign of hypothermia compared to other ECG changes like bradycardia and QT prolongation.

1. Osborn Wave (J Wave)
Dr.G.VENKATA RAMANA
MBBS DNB FAMILY MEDICINE

2. • Osborn wave (J wave)
• Positive deflection seen at the J point in precordial and
true limb leads
• Most commonly associated with hypothermia
• These changes will appear as a reciprocal, negative
deflection in aVR and V1
• The J point in the ECG is the point where the QRS
complex joins the ST segment
• It represents the approximate end of depolarization and
the beginning of repolarization as determined by the
surface ECG
• There is an overlap of around 10ms
• The J point may deviate from the baseline in early
repolarization, epicardial or endocardial ischemia or injury,
pericarditis, RBBB, LBBB, RVH, LVH or digitalis effect

3. J point in a) normal; b) J point elevation; c) with Osborn wave (J wave);
d) J point depression
Note: The letter J on the ECG defines 2 totally different and unrelated events
The J point is a point in time marking the end of the QRS and the onset of the ST
segment present on all ECGs
The J wave is a much less common, slow deflection of uncertain origin originally
described in relation to hypothermia

4. • Osborn Wave Causes
• Characteristically seen in hypothermia (typically T < 30C), but they
are not pathognomic
• Causes of non-hypothermic Osborn waves include:
• Hypercalcemia
• Acute myocardial ischemia
• Takotsubo cardiomyopathy
• Left ventricular hypertrophy due to hypertension
• Normal variant and early repolarization
• Neurological insults such as intracranial hypertension, severe head
injury and subarachnoid hemorrhage
• Severe myocarditis
• Brugada syndrome
• Le syndrome d’Haïssaguerre (idiopathic VF)
• Compared to other hypothermia-induced ECG abnormalities (e.g.
sinus bradycardia; supraventricular arrhythmias, QT prolongation
and AV block), the Osborn wave is thought to be the most specific

5. Osborn Wave ECG examples
Subtle J waves in mild hypothermia [Temp: 32.5°C (90.5°F)]
The height of the J wave is roughly proportional to the degree of
hypothermia

6. •J waves in moderate hypothermia [Temp: 30°C (86°F)]

7. •J waves in moderate hypothermia. [Temp: 28°C (82.4°F)]

8. •Marked J waves in severe hypothermia [Temp: 26°C (78.8°F)]
•Note “negative” J waves seen in aVR and V1