Rivaroxaban for Intracardiac Thrombosis in the Pediatric Population

The goal of this observational study is to determine the efficacy of rivaroxaban treatment for intracardiac thrombi resolution in pediatric patients (\< 16 years old) diagnosed with intracardiac thrombosis. The main question it aims to answer is: Does rivaroxaban treatment resolve the thrombosis during a 3-month treatment? Participants already taking rivaroxaban as part of their regular medical care for thrombosis resolution. They will undergo monthly visits to check that the treatment is progressing correctly and that no major bleeding has occurred. After 3 months of treatment, they will repeat the radiological imaging investigation to verify the actual resolution of the thrombosis.