Utility of Left Bundle Branch Block as a Diagnostic Criterion for Acute Myocardial Infarction

Acute Myocardial Infarction due to Coronary Artery Embolism in a Patient with a Tissue Aortic Valve Replacement

“…29 The Sgarbossa criteria are the most validated ECG criteria for diagnosing STEMI in the presence of LBBB. 29,30 These ECG criteria include: 1) ST-segment elevation >1 mm concordant with QRS complexes; 2) ST-segment depression >1 mm in lead V 1 , V 2 ; and 3) ST-segment elevation >5 mm discordant with QRS complex. The application of the Sgarbossa criteria has resulted in low sensitivities and high specificities for identifying patients with known LBBB and STEMI.…”

“…The application of the Sgarbossa criteria has resulted in low sensitivities and high specificities for identifying patients with known LBBB and STEMI. [29][30][31] The In patients with a presumed embolic coronary event, TEE has been recommended to identify any potential endocardial source of emboli. 23 low sensitivity limits their utility in clinical practice, as diagnostic tests for AMI need to be highly sensitive to detect most cases.…”

Understanding the ECG Part 4: Conduction blocks

“…These changes may be masked by the ST and T-wave abnormalities that normally occur in LBBB (Bennett, 2013). In a patient with chest pain and LBBB, it is often unclear whether ECG changes are due to ischaemia, or simply the result of conduction block, and in clinical practice less than half of these patients are found to have an occluded coronary artery (Jain et al, 2011;Kontos et al, 2011). Various criteria to differentiate normal LBBB from ischaemic LBBB have been suggested, of which the Sgarbossa is the most widely evaluated (Sgarbossa et al, 1996).…”

Updates on the Electrocardiogram in Acute Coronary Syndromes

“…Of these, 47 (26.5 %) had AMI, but only 9 (5 %) had [ 70 % stenosis, only 6 (3.4 %) had pPCI, and only one had 100 % occlusion. Jain et al reported that, of 35 LBBB patients with suspected ACS referred to The Mayo Clinic over 5 years for pPCI, only 14 had ACS (12 AMI), and only five had occluded culprit arteries [52]. Finally, after adjustment for multiple differences, patients with LBBB who undergo reperfusion therapy for suspected AMI have a better prognosis than STEMI patients with normal conduction (OR for in-hospital mortality, 0.610, CI 0.571-0.655) because they do not, unlike the STEMI patients, actually have occlusion [53].…”