Symptomatic Sinus Bradycardia in a Patient with Solitary Fibrous Tumor/Hemangiopericytoma Treated with Pazopanib.

Pazopanib, a multi-targeted tyrosine kinase inhibitor, is associated with cardiovascular adverse events, such as hypertension, cardiac dysfunction, and thromboembolism. However, symptomatic pazopanib-related bradycardia is uncommon. We herein report a case of symptomatic bradycardia of 35 beats per minute in a patient with solitary fibrous tumor/hemangiopericytoma (SFT/HPC) treated with pazopanib for 1 month. His heart rate recovered to a normal range soon after pazopanib cessation. He restarted pazopanib at a reduced dose, which was continued without SFT/HPC progression or bradycardia recurrence. This case highlights the possibility of bradycardia induced by pazopanib and the importance of monitoring the patient's heart rate.