['The aim of this study was to demonstrate the usefulness of leg raise in identifying lower diastolic functional reserve to exercise.', 'One hundred fifty-four patients with abnormal left ventricular relaxation on Doppler mitral inflow with preserved left ventricular ejection fractions were enrolled. After resting evaluations, Doppler echocardiographic measurements were repeated during passive leg raise and graded supine bicycle exercise.', "Patients were divided into 3 groups according to resting E/e' ratio and its response to leg raise: group IA (persistent E/e' < 15 [n = 112]), group IB (change to E/e' > or = 15 after leg raise [n = 19]), and group II (persistent E/e' > or = 15 [n = 23]). Group II had lower S', e', and diastolic reserve index values during exercise compared with group IA but not with group IB. Group IB had higher E/e' ratios during exercise and lower diastolic functional reserve index values accompanied by lower exercise capacity compared with group IA."] Is passive leg-raise helpful to identify impaired diastolic functional reserve during exercise in patients with abnormal myocardial relaxation?