Osborn Wave (J Wave)

Osborn Wave (J Wave) Overview

The Osborn wave (J wave) is a positive deflection at the J point (negative in aVR and V1). It is usually most prominent in the precordial leads

Eponymously associated with John Jay Osborn (1917-2014) following his 1953 ‘current of injury‘ description in hypothermic dogs

ECG J point J wave J point elevation
J point in a) normal; b) c) J point elevation; d) J point depression; e) with J wave (Osborn wave)

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 ECG’s; the J wave is a much less common long slow deflection of uncertain origin originally described in relation to hypothermia.


  • The ECG finding of a positive deflection at the J point (negative in aVR and V1) with a dome or hump configuration is most frequently termed a J wave or Osborn wave.
  • No definitive physiological cause for the deflection despite numerous postulates.
  • Broad differential diagnosis of prominent Osborn waves including hypothermia; benign early repolarization; hypercalcaemia and the Brugada syndrome.
  • In the setting of hypothermia this phenomenon is most commonly referred to as an Osborn wave. 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

Osborn Wave Causes

Characteristically seen in hypothermia (typically T<30C), but they are not pathognomonic. J waves may be seen in a number of other conditions:

Osborn Wave ECG examples

Example 1

ECG Subtle Osborn wave J wave hypothermia
  • 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

Example 2

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

Example 3

J waves Osborn Wave hypothermia temp 30°C
  • J waves in moderate hypothermia. [Temp: 28°C (82.4°F)]

Example 4

Osborn wave temp 26 hypothermia
  • Marked J waves in severe hypothermia [Temp: 26°C (78.8°F)]

Eponymous History of the Osborn Wave

1922 – Kraus described a J-point deflection in hypercalcemic conditions

1938 – Tomashewski described in a hypothermic patient

1950 – Bigelow described ECG changes in hypothermic dogs as:

characterized by a doubling of the QRS interval, and lengthening of the QT interval by three to four times. The T-wave is long and irregular, and usually inverted.

1953 – Osborn studied the effect of hypothermia on the respiratory and cardiac function in dogs. Experimentally-induced hypothermia caused the development of a distinct deflection at the J point on the ECG and resulted in ventricular fibrillation. He called this deflection the ‘current of injury’. [Osborn JJ. Am J Physiol. 1953 Dec;175(3):389-98]

Osborn Current of Injury

Osborn considered acidaemia induced by hypothermia as a primary cause of the Osborn wave, because it disappeared if the arterial pH was normalized by hyperventilation during the same degree of cooling

1959 Emslie-Smith (British Heart Journal, …changes in the ECG in hypothermia.) ‘The characteristic deflection of hypothermia has sometimes been named after Osborm who discussed it in 1953.’

1961 Duguid (The Lancet, Accidental hypothermia) ‘The electrocardiogram may show the distinctive ‘J’ or ‘Osborn’ wave’

1996 – Yan and Antzelevitch provided first direct evidence in support of the hypothesis that:

heterogeneous distribution of a transient outward current-mediated spike-and-dome morphology of the action potential across the ventricular wall underlies the manifestation of the electrocardiographic J wave. The presence of a prominent action potential notch in epicardium but not endocardium is shown to provide a voltage gradient that manifests as a J (Osborn) wave or elevated J-point in the ECG

Many alternate names have been assigned in medical literature including ‘camel hump sign of Osborne‘; ‘hypothermic hump‘; ‘late delta wave’; ‘hathook junction’; ‘J wave’; ‘H wave’ and ‘K wave’

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Emergency physician MA (Oxon) MBChB (Edin) FACEM FFSEM with a passion for rugby; medical history; medical education; and informatics. Asynchronous learning #FOAMed evangelist. Co-founder and CTO of Life in the Fast lane | Eponyms | Books | vocortex |

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