Cardiac Rhabdomyoma

Cardiac rhabdomyoma is a rare, benign mesenchymal tumor of striated muscle origin and represents the most common primary cardiac tumor in the pediatric population, typically diagnosed before the age of 1. While rhabdomyomas can occur in both cardiac and extracardiac locations, the extracardiac forms—classified as adult, fetal, and germ cell tumors—most often involve the head and neck. Cardiac rhabdomyomas are histologically regarded as hamartomas and strongly associated with tuberous sclerosis complex, or Bourneville disease. They most frequently arise within the ventricular myocardium, followed by the atria, cavoatrial junction, and epicardial surface in descending order of prevalence. These tumors are often multiple and tend to regress spontaneously, making conservative management appropriate unless symptoms occur. Clinical manifestations result primarily from obstruction of cardiac inflow or outflow tracts, leading to congestive heart failure, or from arrhythmogenic effects. The latter can range from bradycardia due to sinus or atrioventricular (AV) node dysfunction to more complex tachyarrhythmias, including atrial or ventricular tachycardia, AV nodal reentrant tachycardia, and ventricular preexcitation.