While the presence of atrioventricular (AV) dissociation during wide complex tachycardia is highly specific for a ventricular origin, this finding is often not present or is difficult to discern on the surface electrocardiogram (ECG). Most physicians understand that the pivotal diagnostic challenge focuses on determining whether the tachyarrhythmia is of supraventricular (with aberrant ventricular conduction) or ventricular origin. Even the presence of hemodynamic stability is not helpful in determining the tachycardia mechanism. The process of determining the correct diagnosis can be confusing and cumbersome. He is a frequent EMS conference speaker and contributor to various EMS training texts, and is the author of the popular blog A Day In the Life of an Ambulance Driver, ' En Route: A Paramedic's Stories of Life, Death and Everything In Between,' and 'On Scene: More Stories of Life, Death and Everything In Between.' You can follow him on Twitter ( Facebook, LinkedIn, or email him at Kelly is a member of the EMS1 Editorial Advisory Board.The evaluation of wide QRS complex tachycardia (WCT) remains a common clinical dilemma. Kelly has been recognized as the 2016 Louisiana Paramedic of the Year, 2002 Louisiana EMS Instructor of the Year and 2002 Louisiana AHA Regional Faculty of the Year, and with the 2012 Maggie Award for Best Regularly Featured Web Column/Trade and the 2014 Folio Eddie Award for Best Online Column. He has an Associate of General Studies degree from Louisiana State University at Eunice, Nunez Community College.

He is president of the Louisiana Society of EMS Educators and a board member of the LA Association of Nationally Registered EMTs. He has spent the past 24 years as a field paramedic, critical care transport paramedic, field supervisor and educator. Kelly Grayson, NRP, CCP, is a critical care paramedic in Louisiana. However, even lower sensitivity is still better than throwing up your hands and saying that it can't be done.įor a more in-depth discussion of Sgarbossa's Criteria and other techniques to recognize ischemia in the presence of LBBB, check out Tom's blog, EMS 12 Lead, or this excellent video tutorial by Dr. Criteria C is the weakest criteria of the three, and may indicate a STEMI only 50% of the time. The middle beat illustrates Sgarbossa Criteria C, ≥ 5 mm excessive discordance. Inappropriate concordance of ≥ 1 mm is highly predictive of STEMI. In the beat on the right, you'll note inappropriate concordance in a lead with a negative QRS (Sgarbossa Criteria B). In the beat on the left, you'll note inappropriate concordance in a lead with a positive deflection of the QRS (Sgarbossa Criteria A). Now, when the EKG shows inappropriate concordance (J-point and ST-segment elevation in positive leads, and J-point and ST-segment depression in negative leads), there is a 90% likelihood that the patient is having a STEMI. This is known as discordance, and a small amount of discordance is appropriate and expected in LBBB, as demonstrated in the illustration below: In other words, in those leads where the QRS complex is normally a positive deflection, the J-point and ST-segment should be slightly below the isoelectric line, and in those leads where the QRS is negative (primarily V 1-V 3), the J-point and ST-segment should rise slightly above the isoelectric line. Normally, in LBBB, we'd expect the J-point or ST segment to move in opposite direction of the QRS complex. Sgarbossa's Criteria, in simplest terms, rely on the presence of inappropriate concordance or excessive discordance. That criteria is now widely accepted in clinical practice, and may yield valuable clues allowing the astute clinician to call for timely activation of the cath lab. Elena Sgarbossa's developed criteria for recognizing ischemia in the presence of LBBB. The 2013 STEMI Guidelines endorsed by the AHA state that new or presumed new LBBB is no longer considered an indicator or equivalent of STEMI, and there is indeed a method to diagnose STEMI in the presence of a left bundle branch block. Turns out, neither of those things is necessarily true.

For patients presenting with acute ischemic chest pain, the AHA places the 12-lead ECG at the center of the clinical decision making pathwayĪnd one thing stressed in those lessons is that diagnosis of anterior STEMI was impossible in the presence in the presence of left bundle branch block, and that a newly-occurring LBBB was a STEMI equivalent.

Lbbb vs ivcd