IJCS | Volume 31, Nº4, July / August 2018

DOI: 10.5935/2359-4802.20180027 433 REVIEW ARTICLE International Journal of Cardiovascular Sciences. 2018;31(4)433-442 Mailing Address: Jacqueline Aparecida Borges Rua Martins Ferreira, 81/704. Postal Code: 22271-010, Botafogo, Rio de Janeiro, RJ - Brazil. E-mail: jackborges@yahoo.com; jborges@inca.gov.br Fatigue: A Complex Symptom and its Impact on Cancer and Heart Failure Jacqueline Aparecida Borges, Mônica Maria Pena Quintão, Sergio S. M.C. Chermont, Hugo Tannus Furtado de Mendonça Filho, Evandro Tinoco Mesquita Universidade Federal Fluminense (UFF), Niterói, RJ - Brazil Manuscript received April 11, 2017, revised manuscript December 12, 2017, accepted December 19, 2017. Heart Failure / physiopathology; Neoplasms / physiopathology; Cardiotoxicity / complications; Ventricular Dysfunction, Left; Neoplasias / drug therapy. Keywords 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. Themechanisms involved in fatigue, froma 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. Introduction The survival rate of patients with cancer has improved substantially in recent decades with the emergence of new chemotherapeutic agents and advancement of radiotherapy. However, oncological patients are more susceptible to cardiotoxic effects developed during treatment, which can increase the morbidity and mortality of this population. 1 Within this new scenario, oncocardiology emerged as a new area of specialization based on a multidisciplinary integrative approach. Oncocardiology seeks to improve the quality of cardiologic care offered to patients with cancer, and to study the different dimensions of cardiotoxicity. Among cardiovascular symptoms, fatigue is a common and very prevalent clinical manifestation in patients with cancer, and its characterization and mechanisms still defy healthcare professionals. Fatigue associated with cancer is a subjective experience characterized by fatigue not relieved by sleep or rest, and is considered a predictor of decreased personal satisfaction and quality of life. 2 The symptom fatigue varies in duration and intensity, reduces in varying degrees the patient’s ability to develop daily activities, and decreases the functional capacity of patients with cancer. 3 Fatigue can affect 80-99% of the patients with cancer treated with chemotherapy and/or radiotherapy 4 andmay persist for months to years. Cella et al. 5 reported that one-third of the patients cured of cancer showed fatigue for 5 years after the end of chemotherapy.