Tuesday, February 7, 2012

J-waves after ROSC and Intra-arrest Therapeutic Hypothermia

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.

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.

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.

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.

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
  1. Antzelevitch C, Yan GX. J Wave Syndromes. Heart Rhythm. 2010; 7(4):549-558. [FullText]
  2. 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]
  3. Edelman ER, Joynt K. J Waves of Osborn Revisited. J Am Coll Cardio. 2010; 55(20):2287. [PubMed]
  4. Dr. Smith's ECG Blog: Osborn Waves and Hypothermia.

4 comments:

ECG Interpretation said...

Great case with wonderful illustration of Osborn waves at their finest! Another possible contribution to shrinkage of the giant Osborn waves may have been that the salvos of VT resolved (post-ectopic effect on ST-T wave ... - with previously the largest Osborn wave being in the lead with the salvo). Again - GREAT case & illustrations by Christopher!

ekgcasestudies (formerly jarvik7) said...

Beautiful case presentation and very interesting set of 12-leads. Your hypothesis in re normalization associated with pH equilibration is intriguing. I wonder two things: first, what was the pt.'s core temp on arrival, and what was her pH on ABG. Failing ABG, how high was the CO2? It is understandable if this info is not available, but still I wonder.

As always, excellent analysis, graphics, and references! Thanks for this thought provoking case study!

Christopher said...

I had based the hypothesis off of one of the Fenstad paper. Her temp at the hospital was not available to me, nor were her lab values unfortunately.

ekgcasestudies said...

Just read the reference and I copy your reasoning; thanks again for the great case study.