A significant clinical problem is patients presenting with exercise-limiting dyspnoea, sometimes with associated
chest pain, in the absence of detectable left ventricular (LV) systolic dysfunction, coronary artery disease, or lung
disease. Often the patients are older, female, and have isolated basal septal hypertrophy (BSH), frequently on a background
of mild hypertension. The topic of breathlessness in patients with clinical heart failure, but who have a normal
ejection fraction (HFNEF) has attracted significant controversy over the past few years. This review aims to analyse the
literature on BSH, identify the possible associations between BSH and HFNEF, and consequently explore possible pathophysiological
mechanisms whereby clinical symptoms are experienced.