If you are a paramedic and learned to read ECGs, you are an expert at locating the J-point. It’s not hard to do; the J-point is the point in the ECG where the QRS complex joins the ST segment. Simply put, it represents the end of the ventricular contraction. When the J-point deviates from the baseline along with the ST-segment, we should become a little concerned. We will quickly look for the infamous STEMI, or try to identify a STEMI imitators like early repolarization or a bundle branch block, to name a few. But when the J-point itself forms a deflection, spike or dome, or like I like to call it a “bump”, we refer to this most commonly as an Osborn wave.
Pictures copyright J.A.M.B-ing
It is called an Osborn wave, as you may have guessed, because it was named after a doctor named Osborn - although he was neither the first to discover this deflection nor describe it. A quick search on Wikipedia will present you with other names for this wave, such as late delta wave, prominent J wave, hathook junction, hypothermic wave, and my favorite, the camel-hump sign.
J-waves--or Osborn waves--appreciated in the lateral precordial leads
Picture courtesy of sixlettervariable.blogspot.com/. Reproduced with permission.
The causes for an Osborn wave are varied. Hypothermia and hypercalcemia are some of the more common reasons, however - to keep with the current topic of this blog - brain injury, subarachnoid hemorrhage, and damage to sympathetic nerves in the neck have been reported to cause this wave, too.
How about that?
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