Left lateral atriofascicular accessory pathway as a unique atrioventricular connection.

In this case report, we describe a 74-year-old woman with paroxysmal tachycardias. During the electrophysiological study, a change in the QRS morphology and peculiar features of the diseased AV node complicated the diagnosis. A rare left atriofascicular accessory pathway as the sole anterograde connection between atria und ventricles was revealed, underscoring the importance of meticulous electrophysiological assessment.