J wave explained

A J wave — also known as Osborn wave, camel-hump sign, late delta wave, hathook junction, hypothermic wave,^[1] K wave, H wave or current of injury — is an abnormal electrocardiogram finding.^[2]

J waves are positive deflections occurring at the junction between the QRS complex and the ST segment,^{[3] [4]} where the S point, also known as the J point, has a myocardial infarction-like elevation.__TOC__

Causes

They are usually observed in people suffering from hypothermia with a temperature of less than 32 °C (90 °F),^[5] though they may also occur in people with very high blood levels of calcium (hypercalcemia), brain injury, vasospastic angina, acute pericarditis, or they could also be a normal variant. Osborn waves on ECG are frequent during targeted temperature management (TTM) after cardiac arrest, particularly in patients treated with 33 °C.^[6] Osborn waves are not associated with increased risk of ventricular arrhythmia, and may be considered a benign physiological phenomenon, associated with lower mortality in univariable analyses.

History

The prominent J deflection attributed to hypothermia was first reported in 1938 by Tomaszewski. These waves were then definitively described in 1953 by John J. Osborn (1917–2014) and were named in his honor.^[7] Over time, the wave has increasingly been referred to as a J wave, though is still sometimes referred to as the Osborn wave in most part due to Osborn's article in the American Journal of Physiology on experimental hypothermia.^[8]

Notes and References

1. Aydin M, Gursurer M, Bayraktaroglu T, Kulah E, Onuk T . Prominent J wave (Osborn wave) with coincidental hypothermia in a 64-year-old woman . Tex Heart Inst J . 32 . 1 . 105 . 2005 . 15902836 . 555838 .
2. Maruyama M, Kobayashi Y, Kodani E, etal . Osborn waves: history and significance . Indian Pacing Electrophysiol J . 4 . 1 . 33–9 . 2004 . 16943886 . 1501063 .
3. Web site: ecg_6lead018.html . 2008-12-20.
4. Web site: THE MERCK MANUAL OF GERIATRICS, Ch. 67, Hyperthermia and Hypothermia, Fig. 67-1 . 2008-12-20.
5. Book: Marx, John . Rosen's emergency medicine: concepts and clinical practice 7th edition . 2010 . Mosby/Elsevier. Philadelphia, PA . 978-0-323-05472-0 . 1869 .
6. Hadziselimovic . Edina . Thomsen . Jakob Hartvig . Kjaergaard . Jesper . Køber . Lars . Graff . Claus . Pehrson . Steen . Nielsen . Niklas . Erlinge . David . Frydland . Martin . Wiberg . Sebastian . Hassager . Christian . July 2018 . Osborn waves following out-of-hospital cardiac arrest—Effect of level of temperature management and risk of arrhythmia and death . Resuscitation . en . 128 . 119–125 . 10.1016/j.resuscitation.2018.04.037. 29723608 .
7. Osborn . J. J. . Experimental hypothermia: Respiratory and blood pH changes in relation to cardiac function . Am J Physiol . 1953 . 175 . 3 . 389–398 . 10.1152/ajplegacy.1953.175.3.389 . 13114420 . free .
8. Serafi . S. . Vliek . C. . Taremi . M. . 2011 . Osborn waves in a hypothermic patient . Journal of Community Hospital Internal Medicine Perspectives . 1 . 4 . Article: 10742 . 10.3402/jchimp.v1i4.10742. 3714046 . 23882340 . free .