How does the rate of MI compare among patients with a new LBBB, old LBBB, or no LBBB who present to the ED with chest pain or ischemic equivalent?

About the same according to a recent article published by Chang et al in the American Journal of Emergency Medicine.

Rate of MI among the different groups:

• new LBBB = 7.3%
• old LBBB = 5.2%
• no LBBB = 6.1%

P value = 0.75

Results raise the question whether all new LBBB in the setting of chest pain or ischemic equivalent should be treated as ST elevation MI per present American College of Cardiology and American Heart Association guidelines.

Click here to read some excellent commentary on these results by Dr. Amal Mattu.


Source

Chang, A. et al. "Lack of association between left bundle-branch block and acute myocardial infarction in symptomatic ED patients" American Journal of Emergency Medicine. 2009.