Low Dose Radiotherapy for Heart Failure

Inclusion Criteria * Age \>18 years; * Clinical and laboratory diagnosis of chronic systolic HF grades II or III of the New York Heart Association with ejection fraction \<40%; * Refractoriness to standard clinical treatment; defined as the persistence of HF signs and symptoms despite optimized drug therapy. * Patient consent to participate in the study. * Agreement to adopt contraceptive practices/methods until the end of the intervention for women of childbearing age. Exclusion Criteria * Patients who have undergone any type of previous radiotherapy in the thoracic region; * Patients who have undergone heart transplants; * Contraindications for magnetic resonance imaging (MRI), such as the use of metal implants or prostheses. * Pregnant patients.