October 10, 2020

From Oct 6th – 8th, 2020, Haney Mallemat (@CriticalCareNow) and his team put on an absolutely amazing online critical care conference called ResusX Rewired.  ResusX is a conference designed by resuscitationists to provide clinicians with the most up to date skills and knowledge to help make a difference in your patients' lives.  Haney and his crew made a combination of short-format, high-yield lectures, and completely customizable small group sessions with procedural demos seem easy.  There were so many high-quality speakers and pearls that I learned from this conference that I wanted to archive them here in one post for reference and to share with our readers/followers.

January 11, 2016

Background: Left Bundle Branch Block (LBBB) on the ECG makes accurate recognition of ST-Elevation Myocardial Infarction (STEMI) rather difficult. The 1996 and 2004 American College of Cardiology/American Heart Association (ACC/AHA) STEMI guidelines recommended immediate reperfusion therapy for patients with potentially ischemic symptoms and new, or presumed new, LBBB. In 2013, this recommendation was removed from the guidelines. Historically, reperfusion decisions in LBBB have been determined by the original Sgarbossa criteria published in 1996, but there are three key limitations to the original study by Sgarbossa et al:
  1. The original Sgarbossa criteria (i.e. the “weighted” Sgarbossa criteria) depends on a point system that rely on 3 findings, only 2 of which would provide enough points (i.e. 3) to make the diagnosis of AMI. Using the Sgarbossa criteria without the point system (i.e. the “unweighted” Sgarbossa criteria) increases sensitivity but decreases specificity.
  2. Sgarbossa et al diagnosed AMI by creatine kinase MB (CK-MB) elevations instead of angiographic evidence of acute coronary occlusion (ACO), which limits the sensitivity of the rule because it combines NSTEMI and STEMI patients in the outcome definition
  3. Finally, Sgarbossa et al used an absolute criterion (5mm) rather than a proportional criterion for excessively discordant ST elevation lowering the sensitivity of the criteria.
The modified Sgarbossa criteria replaces the absolute 5mm discordant ST elevation with a proportion (ST elevation/S-wave amplitude ≤ -0.25). In other words, the modified Sgarbossa criteria only changes the last of the original Sgarbossa criteria with the first two criteria staying intact. Now, if any of these criteria are met, the cardiac catheterization lab should be activated. We have written on REBEL EM before about the modified Sgarbossa criteria and one of our conclusions was this rule looked very promising, but needed an external validation study. Well that study is now here and for full disclosure I am one of the authors on the paper.

December 3, 2013

The recognition of ST-segment elevation myocardial infarction (STEMI) in the presence of left bundle-branch block (LBBB) remains difficult and frustrating to both emergency medicine physicians and cardiologists.  According to the 2004 STEMI guidelines, emergent reperfusion therapy was recommended to patients with suspected ischemia and new LBBB however, the new 2013 STEMI guidelines made a drastic change by removing this recommendation.  Several papers have recently been published discussing a modified Sgarbossa's criteria and a new algorithm to help decrease false cath lab activation and/or fibrinolytic therapy but, are they ready for primetime?