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


  • 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’


  • Kraus F. Uber die wirkung des kalziums auf den kreislauf. Dtsch Med Wochenschr. 1920;46:201–203.
  • Kraus F, Zondek SG. Uber die Durchtrankungsspannung. Klin Wochensch I Jahrgang. 1922; 36: 1778-1779.
  • Tomaszewski W. Changements electrocardiographiques observes chez un homme mort de froid. Arch Mal Coer. 1938;31:525.
  • Bigelow WG, Lindsay WK, Greenwood WF. Hypothermia; its possible role in cardiac surgery: an investigation of factors governing survival in dogs at low body temperatures. Ann Surg. 1950 Nov;132(5):849-66. [PMC1616603]
  • Osborn JJ. Experimental hypothermia; respiratory and blood pH changes in relation to cardiac function. Am J Physiol. 1953 Dec;175(3):389-98. [PMID 13114420]
  • Gussak I, Bjerregaard P, Egan TM, Chaitman BR. ECG phenomenon called the J wave. History, pathophysiology, and clinical significance. J Electrocardiol. 1995 Jan;28(1):49-58. [PMID 7897337]
  • Emslie-Smith D, Sladden GE, Stirling GR. The significance of changes in the electrocardiogram in hypothermia. Br Heart J. 1959 Jul; 21(3): 343–351. [PMC1017590]
  • Maruyama M et al. Osborn Waves: History and Significance. Indian Pacing Electrophysiol J. 2004 Jan-Mar; 4(1): 33–39. [PMC1501063]
  • Rituparna S et al. Occurrence of “J Waves” in 12-Lead ECG as a Marker of Acute Ischemia and Their Cellular Basis. Pacing Clin Electrophysiol. 2007 Jun; 30(6): 817–819. [PMC1989774]
  • Hurst JW. Naming of the waves in the ECG, with a brief account of their genesis. Circulation. 1998 Nov 3;98(18):1937-42. [PMID 9799216]
  • Yan GX, Antzelevitch C. Cellular basis for the electrocardiographic J wave. Circulation. 1996 Jan 15;93(2):372-9. [PMID 8548912]
  • Haïssaguerre M, et al. Sudden cardiac arrest associated with early repolarization. N Engl J Med. 2008 May 8;358(19):2016-23. PMID: 18463377
  • Otero J, Lenihan DJ. The “normothermic” Osborn wave induced by severe hypercalcemia. Tex Heart Inst J. 2000;27(3):316-7. PMID: 11093425

ECG Library Basics

LITFL Further Reading

Advanced Reading




Posted by Dr Mike Cadogan

Emergency physician with a passion for medical informatics and medical education/textbooks. Asynchronous learning #FOAMed evangelist | @sandnsurf | + Mike Cadogan | LinkedIn

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.