J wave
A J wave — also known as Osborn wave, camel-hump sign, late delta wave, hathook junction, hypothermic wave, K wave, H wave or current of injury — is an abnormal electrocardiogram finding. J waves are positive deflections occurring at the junction between the QRS complex and the ST segment, where the S point, also known as the J point, has a myocardial infarction-like elevation. Causes. They are usually observed in people suffering from hypothermia with a temperature of less than 32 °C (90 °F), though they may also occur in people with high blood levels of  calcium (hypercalcemia), brain injury, vasospastic angina, acute pericarditis, or ventricular fibrillation and could also be a normal variant. 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. 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.