Why is there ST elevation in LBBB?
Why is there ST elevation in LBBB?
Assessment of ischemia on ECG is difficult in the presence of left bundle branch block. This is because left bundle branch block causes substantial changes in left ventricular de- and repolarization, which result in (secondary) ST-T changes.
Which criteria can be used to determine STEMI in the presence of LBBB?
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)
Why is LBBB a stemi mimic?
This is further complicated because an LBBB itself is a risk factor for cardiac death and any new LBBB can be the presenting ECG pattern in a proximal left anterior descending coronary artery (LAD) occlusion. Thus, a new LBBB ECG pattern in patients with a compatible clinical scenario is considered a STEMI equivalent.
Can you assess the ST segment with LBBB?
The presence of a left bundle branch block (LBBB) on EKG can make recognition of an acute ST segment elevation myocardial infarction (STEMI) difficult.
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 diagnostic criteria for LBBB?
LBBB is often detected on ECG. Diagnostic criteria are defined by the American College of Cardiology (ACC) and American Heart Association (AHA) as follows: Rhythm must be of super-ventricular origin (EG: ventricular activation coming from atrial or AV nodal activation)
Is LBBB still an indication for emergent reperfusion?
It is important to remember that the latest (2013) ACC/AHA STEMI guidelines removed New Left Bundle Branch Block (LBBB) as an indication for emergent reperfusion because there are too many false positives. A reader sent this: An elderly female presented with dyspnea, nausea, diaphoresis, and indigestion at 2am.
What is the prognosis of LBBB (lumbar bradycardiomyositis)?
Although LBBB is often associated with significant heart disease and is often the result of myocardial injury, strain or hypertrophy, it can also be seen in patients without any particular clinical disease. In isolation the presence of LBBB does not lend itself to any specific clinical concern, nor does it affect prognosis.
