Since Japan is experiencing a super-aged society, the number of heart failure patients (HF) is increasing remarkably. In particular, the increase in heart failure with preserved ejection fraction (HFpEF), which is common in the elderly, has characterized the last decade. The diagnosis of HFpEF by assessment of left ventricular (LV) diastolic dysfunction, which is also referred to as diastolic heart failure, is an important role assigned to echocardiography. The Doppler echocardiographic algorithm for the evaluation of LV diastolic function from the American Society of Echocardiography (ASE) and the European Association of Cardiovascular Imaging (EACVI) has been widely used to diagnose HFpEF. This article will focus on the HFpEF diagnostic algorithm proposed in 2018 by the Heart Failure Association of the European Society of Cardiology (HFA-PEFF score) based on autologous elderly cases. We compared the usefulness of the HFA-PEFF score with the ASE/EACVI algorithm. By comparing HFpEF patients with healthy elderly subjects and hypertensive patients with no history of HF, this paper will identify the usefulness and challenges of the HFA-PEFF score in the assessment of the elderly. The echocardiographic findings in at-risk or early-stage elderly patients with HFpEF will also be summarized. In addition, this review will describe future prospects for echocardiographic diagnostic systems for the prevention of HF onset and HF progression in the elderly and propose the concept of “early HFpEF”.