Can you diagnose STEMI with LBBB?
Can you diagnose STEMI with LBBB?
The diagnosis of STEMI in LBBB is dependent on the “Rule of Appropriate Discordance,” which means that, in normal LBBB (without MI), the ST segment (and usually T-wave) are in the opposite direction (discordant to) the majority of the QRS.
What criteria for a LBBB the ECG include?
The ECG criteria for a left bundle branch block include:
- QRS duration greater than 120 milliseconds.
- Absence of Q wave in leads I, V5 and V6.
- Monomorphic R wave in I, V5 and V6.
- ST and T wave displacement opposite to the major deflection of the QRS complex.
Is a new LBBB still a STEMI equivalent?
The most recent 2013 STEMI guidelines are more consistent with our recommendations and recognize the challenge and uncertainty of diagnosing an MI in the presence of LBBB. In the recent version of the guidelines, LBBB is no longer an automatic STEMI equivalent.
Is a left bundle branch block a STEMI?
A STEMI is generally defined as an Electrocardiogram (EKG) with ST elevation of greater than 1 mm in 2 or more contiguous leads. It has also been defined as a “new” Left Bundle Branch Block (LBBB) in the setting of chest pain by the guidelines of the American College of Cardiology/American Heart Association.
What are the secondary changes in LBBB?
Abnormal repolarization results in secondary ST-T changes, including ST elevations (leads V1–V3), ST depressions (leads V4, V5, V6, aVL, I) and inverted T-waves (seen in leads with ST depressions). Such ST-T changes are always normal (expected) in the presence of LBBB.
What is the difference between LBBB and STEMI?
In LBBB, the initial left to right activation of the septum is absent. In the 2004 guidelines for the management of ST segment elevation myocardial infarction (STEMI), new or presumably new LBBB was considered as equivalent to STEMI.
How is STEMI diagnosed in patients with LBBB with Sgarbossa syndrome?
Detection of an STEMI in patients with an underlying LBBB can be challenging but it is not impossible. The presence of a Sgarbossa criteria score > 3 should prompt immediate cardiac catheterization lab activation.
What is the criteria for diagnosing a STEMI?
Back in 1996, Dr. Sgarbossa created criteria for diagnosing a STEMI on a 12 lead in the presence of a LBBB. There was three criteria in that meant there was a STEMI: Concordant ST depression that is greater than 1 mm in V1-V3. Concordant ST elevation that is greater than 1 mm in any lead.
What are the criteria for LBBB?
LBBB Criteria 1 QRS > 120 msec. 2 Dominant S wave in V1 (due to proximity of lead V1 to RV). 3 Broad R waves in the lateral leads (I, aVL, V5-6) that are monophonic. 4 Absence of Q waves in the lateral leads (I, V5-6). 5 R wave peak time is prolonged (> 60 msec) in V5-6.
