Highlights • Cardiac rhabdomyomas may alter intracardiac electrical conduction. • Rhabdomyoma arrhythmias are caused by isolated atrial depolarization disturbances. • Destruction of conduction system has been described in diffuse rhabdomyomatosis.
Introduction Rhabdomyomas are the most frequent cardiac tumors in children. Furthermore, they are often associated to tuberous sclerosis complex, an autosomal dominant neurocutaneous disorder characterized by tumor-like malformations that involve many organ systems. Presentation of the case We describe a rare ECG pattern in a severe case of neonatal tuberous sclerosis complex. Discussion In the presence of significant rhabdomyomatosis related to tuberous sclerosis, multiple clusters of rhabdomyoma-like cells can infiltrate the myocardium, with increased fibrosis areas. Conclusion Considering the fact that rhabdomyomas often show spontaneous regression, close follow-up is sufficient in hemodynamically stable cases. Destruction of the conduction system, with arrhythmias as consequence, can be the presenting feature of diffuse rhabdomyomatosis.