Transient right bundle-branch block in anterior descending coronary occlusion

Coexistent acute coronary syndrome with bundle-branch block can have a poor outcome, and primary percutaneous coronary intervention is an option for patients with persistent ischemic symptoms and a recent right bundle-branch block (RBBB). This condition poses a diagnostic challenge, with differentiation from transmural ischemia and ST-elevation myocardial infarction (STEMI), beside which, new-onset RBBB can follow acute myocardial infarction. As new-onset transient RBBB in a patient with STEMI carries high risk for short-term mortality, emergency invasive stratification should be performed at the earliest possible. The aim of this case study is to enhance the suspicion index of primary health care workers about this clinical entity, which may evolve when unsuspected, misdiagnosed or not well-controlled.