The following is the post-resuscitation 12-Lead electrocardiogram of an 82 year old female who received intra-arrest therapeutic hypothermia, via chilled saline and ice packs, as part of a new protocol for cardiac arrest management. The patient also received three defibrillations and was administered epinephrine, naloxone, and amiodarone during the resuscitation.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhrJRuEzJzELVtYx_8q_YM4P31I8bKfQ0OhnGUpenkSdXjaeb3KuiQBcKb2KHcfR14iufZ6g_OLhjE4vZ0URD1ACQEPeFaNzBTb0bsRCfC71bs17sn5KaomgZ_Qso_Ay9zi1d9cY03Axgh5/s400/82yo+F+-+Cardiac+Arrest+-+ROSC+-+Initial+12-Lead.jpg) |
12-Lead ECG obtained approximately 5 minutes after ROSC |
The post arrest 12-Lead ECG shows a sinus rhythm with frequent premature atrial and ventricular ectopic complexes. The LifePak 12, which uses the GE Marquette 12SL algorithm, displayed the ominous
*** ACUTE MI SUSPECTED *** message and suggested a lateral injury pattern.
Closer inspection of the lateral precordial leads reveals the ST-elevations present are actually giant J-waves, or Osborn waves.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj1oYVR-GEEGj9PvwqDYsDuZ53aPu0MZgMEkMqrtQyXF6e5tM0bn-zQ-QCMaF8OKXtbj3sU0C2v8ecRRNGYrd3gI19hAAP68oifeBD2LrXNFEMQZH2V0rNFfSBnBt2qM7zZjQxG-FG4pLEv/s320/82yo+F+-+Cardiac+Arrest+-+V5-V6+Osborn+Waves.jpg) |
J-waves--or Osborn waves--appreciated in the lateral precordial leads |
Recognizing this finding is present, a closer look at the entire 12-Lead ECG shows that subtle J-waves are present in almost every lead group.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj3F1AWlAWf_mzNpLaXr10szgS7QVPyFjHJDZ_D_TzpT6_jUNkICWcEsQVbdqRbW0cCe-rvdrEfGjTlVVW4KT0BgbKz5v9i3Z378IgZ_JEfb6keptEI5XsqtN4eQ7JalyTnmjx3amagxDQs/s400/82yo+F+-+Cardiac+Arrest+-+ROSC+-+Subsequent+12-Lead.jpg) |
Subsequent 12-Lead ECG obtained 17 minutes after ROSC |
A repeat 12-Lead ECG acquired 12 minutes later shows a sinus tachycardia with a single PAC, without the giant J-waves from the initial ECG, diffuse ST/T-wave changes consistent with ischemia are also present. However, small J-point elevation persists in the lateral precordials. The computerized interpretation no longer believes a STEMI-pattern is present and incorrectly identifies the rhythm as atrial fibrillation.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgeyrcPKJ8dzuTJ1zGyuH0f4gsEIh0-KIOWWkf_hCX8WDS3vkryTambI3DUIWRUr8N1gqEnr5kI32keR6kE2FgY7sLk1Pvm7DCIXPs7p_Cz0vuoGeRonh7bLAL0CGonYPrk4IyVJk1RZnmb/s400/82yo+F+-+Cardiac+Arrest+-+Precordial+Comparison.jpg) |
Comparison of the precordial leads between the first and subsequent 12-Lead ECG. |
A side by side look at the precordial leads provides an interesting look at the near resolution of the giant J-waves post-ROSC.
One explanation for the normalization of the traditional electrocardiographic findings of hypothermia may be related to the management of the patient's ventilation both intra-arrest and post-arrest. As the patient's pH normalized with mechanical ventilation and a perfusing rhythm, so did the repolarization abnormalities (visualized as J-waves).
References
- Antzelevitch C, Yan GX. J Wave Syndromes. Heart Rhythm. 2010; 7(4):549-558. [FullText]
- Fenstad ER, et al. Therapeutic hypothermia in out of hospital sudden cardiac arrest: Significance of J-waves. J Am Coll Cardio. 2011; 57(14):Suppl 5, E1002. [PDF FullText]
- Edelman ER, Joynt K. J Waves of Osborn Revisited. J Am Coll Cardio. 2010; 55(20):2287. [PubMed]
- Dr. Smith's ECG Blog: Osborn Waves and Hypothermia.