Fatigue: A Complex Symptom and its Impact on Cancer and Heart Failure

Abstract In chronic diseases like cancer and heart failure (HF), fatigue is a common and complex symptom from an etiological and pathophysiological point of view, thus, a relevant issue in the recent area of oncocardiology. Fatigue is prevalent in 80-90% of the oncological patients treated with chemotherapy and/or radiotherapy and affects approximately 50-96% of the individuals with IC. The toxicity attributed to chemotherapeutic agents can determine the patients’ degree of fatigue and may even predict their survival. In recent decades, the advancement of antineoplastic therapies has substantially impacted the survival of patients with cancer, and the risks of harmful effects from these therapies to the cardiovascular system have been increasingly described. Therefore, the cooperation between oncologists and cardiologists has led to the emergence of oncocardiology and the new concept of cardiac surveillance. Cardiotoxicity is one of the clinical complications in the treatment of cancer, and its typical manifestation is left ventricular systolic dysfunction. New diagnostic and therapeutic strategies have been employed in the cardiac surveillance of patients with cancer. Fatigue in these patients has been carefully studied with a multidisciplinary approach and with the development of visual scales to quantify and correlate better its real impact on these individuals’ quality of life and survival. The Fatigue Pictogram and Piper Fatigue Scale are tools increasingly used in research and clinical practice. The mechanisms involved in fatigue, from a conceptual point of view, may be of central (central nervous system) or peripheral (muscular skeletal) origin, both of which may be present in patients with cancer. The present review aims to discuss the new concepts in the assessment of fatigue in oncological patients. These concepts are fundamental to professionals who work in the emerging area of oncocardiology.