Heart failure is a major health problem which often concerns the elderly. Prevalence of heart failure with preserved systolic function is increasing and varies from 40 to 50%. In the literature, and in the large epidemiological studies, it is commonly designed with the term of "diastolic heart failure", even if a precise analysis of diastolic function is not performed. A diagnostic algorithm is proposed in order to better define the concept of heart failure with preserved systolic function. It consists of seven steps from symptoms and clinical signs to the echocardiographic analysis of diastolic function, in order to confirm the definition of heart failure with preserved systolic function.