ECG J waves

Abstract

Osborne waves, also referred to as J waves, were Þ rst described by Tomaszewkski in 1938. The J wave is a positive convex des ection that occurs at the junction of the QRS complex and ST segment, the J-point. They occur most prominently in the inferior leads: II, III, and aVF and the precordial leads: V5–V6 when the core body temperature falls below 32°C (89.6°F). The magnitude of the des ection above the isoelectric line varies inversely with the fall in core body temperature below 32°C. Computer interpretation of ECG has been found to be unreliable in hypothermia, with the J waves in some cases being mistaken for myocardial injury current. When J waves are seen the differential diagnosis includes hypercalcemia, sepsis, CNS lesion, cardiac ischemia, and Brugada syndrome.