How does LBBB diagnose MI?
How does LBBB diagnose MI?
identified three ECG criteria that may improve the diagnosis of MI in patients with LBBB:
- ST-elevation of ≥1 mm and concordant with the QRS complex (5 points)
- ST-segment depression ≥1 mm in lead V1, V2, or V3 (3 points)
- ST elevation ≥5 mm and discordant with the QRS complex (2 points)
When is Sgarbossa criteria used?
The Sgarbossa criteria is used in the diagnosis of an acute myocardial infarction when a left bundle branch block is present.
How many points is sgarbossa?
0 points. In the original Sgarbossa criteria, a score of <3. typically is not considered diagnostic of acute MI, but also does not rule out MI. In concerning patients, repeating EKGs and cardiac enzymes may be helpful, along with cardiology consultation.
How do you diagnose MI in Rbbb?
MI Diagnosis in RBBB
- Case 1a: Patient with RBBB and inferior MI.
- Case 1b: Lead V4R in the same patient with RBBB and inferior MI clearly shows ST elevation.
- Case 1c: The same patient before acute MI developed.
- Case 2a: RBBB with anterior myocardial infarction.
- Case 2b: ECG from the same patient before the MI occured.
Why is LBBB worse than Rbbb?
In a chronic cardiomyopathy cohort, RBBB is associated with ischemic cardiomyopathy and large anteroseptal scar, while LBBB is associated with nonischemic etiologies. The large myocardial scar in RBBB patients may explain why they have even worse mortality than non-specific LV conduction delay patients receiving CRT.
How do I get Sgarbossa criteria?
The original three criteria used to diagnose infarction in patients with LBBB are:
- Concordant ST elevation > 1mm in leads with a positive QRS complex (score 5)
- Concordant ST depression > 1 mm in V1-V3 (score 3)
- Excessively discordant ST elevation > 5 mm in leads with a -ve QRS complex (score 2)
How accurate is Sgarbossa criteria?
The original, weighted, Sgarbossa criteria (Sgarbossa 1996)) has an excellent specificity at 99%, but only a sensitivity of about 50%.
How can you tell the difference between STEMI and 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.
How do you tell the difference between LBBB and RBBB?
As seen, LBBB is characterized by deep and broad S-waves in V1/V2 and broad and clumsy R-waves in V5/V6. RBBB is characterized by rSR’ complex in V1/V2, meaning that there are two R-waves and a large S-wave. Furthermore, the S-wave in V5/V6 is typically very broad in the presence of RBBB.