Cor Vasa 2019, 61(1):68-71 | DOI: 10.1016/j.crvasa.2017.12.013

Alternating bundle-branch block in acute coronary syndrome

Matic Avsec^a, Misa Fister^b, Marko Noč^b, Peter Radsel^b

^a Surgical Clinic, Emergency Department, University Medical Centre Ljubljana, Ljubljana, Slovenia

^b Department of Internal Intensive Medicine, University Medical Centre Ljubljana, Ljubljana, Slovenia

Background: Bundle-branch blocks often blur ischemic ECG changes. Alternating bundle-branch block is not yet fully understood but can hold clinical significance.

Case report: We present a case of a patient with a known left bundle-branch block (LBBB) who developed a new right bundle-branch block (RBBB) in a setting of acute coronary syndrome. Coronary angiogram revealed subtotal proximal LAD stenosis that was resolved with stent implantation. After the percutaneous coronary intervention RBBB disappeared and LBBB reappeared. The probable reason for the alternating bundle-branch block in the presented case is a new origin of ventricular impulses after initial medical treat- ment. New onset RBBB has been an intriguing clinical entity often associated with acute myocardial infarction. RBBB could be added to ST-elevation myocardial infarction as an equivalent indication for urgent reperfusion therapy. Why should an emergency physician be aware of this? Alternating bundle-branch block can be an indicator of reperfusion, thus changing the management of an acute coronary syndrome patient.

Keywords: Acute coronary syndrome, Coronary angiography, Bundle-branch block, Left bundle-branch block, Right bundle-branch block, Percutaneous coronary intervention

Received: December 16, 2017; Accepted: December 29, 2017; Published: March 21, 2019  Show citation