Pathophysiology of exercise intolerance in breast cancer survivors with preserved left ventricular ejection fraction.

Breast cancer (BC) survival rates have improved during the past two decades and as a result older BC survivors are at increased risk of developing heart failure (HF). Although the HF phenotype common to BC survivors has received little attention, BC survivors have a number of risk factors associated with HF and preserved ejection fraction (HFPEF) including older age, hypertension, obesity, metabolic syndrome and sedentary lifestyle. Moreover, not unlike HFPEF, BC survivors with preserved left ventricular ejection fraction (BCPEF) have reduced exercise tolerance measured objectively as decreased peak oxygen uptake (peak VO2). This review summarizes the literature regarding the mechanisms of exercise intolerance and the role of exercise training to improve peak VO2 in BCPEF.