Accelerated idioventricular rhythm as anginous substrate in elderly: Report of an unprecedented case

•While AIVR is commonly seen as a benign rhythm after myocardial reperfusion, clinicians should remain alert to possible rare symptomatic presentations, such as anginous chest pain, as observed in the described case.•Probably we are talking about an extension of the enigmatic phenomenon of PLBBBS. In this sense, we propose a presentation similar to PLBBBS, but with a different substrate (AIVR), which is characterized by angina concurrent with the sudden appearance of a LBBB pattern on the EKG. Key diagnostic hallmarks include pain alleviation with the resolution of the AIVR rhythm, absence of myocardial ischemia, and a prior and post-block normal EKG.•Given AIVR's rare potential to be the primary cause behind anginal pain, especially when other usual triggers are absent, a broad differential approach becomes essential for clinicians when confronted with prevalent symptoms such as chest pain.•The varied clinical manifestations of AIVR, as shown in this case, underline the importance of comprehensive patient evaluation, even when presented with rhythms traditionally viewed as benign.•We propose a reflection on our limited knowledge from understanding the exact mechanisms behind the varied presentations of one of the most common symptoms in daily clinical practice, such as chest pain. Further analyses are required, reinforcing the importance of scientific publication of more related cases.