The document discusses guidelines for assessing diastolic dysfunction according to the ASE/EACVI 2016 guidelines. It defines diastolic dysfunction and describes the stages from grade I to grade IV. For each grade, it discusses the pathophysiology and key echocardiographic findings including mitral inflow patterns, tissue Doppler measurements, pulmonary vein flow, and left atrial size. The guidelines simplify the assessment of diastolic function into four grades based on parameters of left ventricular relaxation, left atrial pressure, mitral E/A ratio, E/e' ratio, pulmonary vein flow, and left atrial size.