Background Tissue Doppler echocardiography is reported to be a relevant method to determine mechanical intraventricular systolic (DYSs) and early-diastolic (DYSe) dyssynchrony. Nonetheless, few data exist on the effect of preload and heart rate (HR) on DYSs and DYSe in patients with a diastolic dysfunction. Methods We recruited 38 patients (24 men, 61짹12 years) with a diastolic dysfunction based on the mitral inflow and mitral annulus velocity; 24 with a relaxation abnormality (Gr 1), 10 with pseudonormalization pattern (Gr 2), and 4 with restrictive mitral inflow pattern (Gr 3). After obtaining baseline echocardiogram, leg-raising maneuver was performed for 5 minutes in Gr 1 and 1 tablet of sublingual nitroglycerin (SLNG) was given for Gr 2 and Gr 3 to alter preload. DYSs and DYSe were determined by measuring the maximal differences in Ts and Te (defined as time intervals from the QRS onset to the systolic (Ts) and early diastolic (Te) peak velocities) in 4 basal segments derived from the apical 4- and 2- chamber views, respectively. Results There is no difference of ejection fraction between Gr 1 and Gr 2 & 3 (58.3짹11.8 vs 51.6짹16.4 %). DYSs decreased after SLNG administration (75.7짹13.6 vs 53.7짹9.4 msec, p=0.046), whereas it showed a significant increment after leg-raising (76.6짹6.9 vs 88.8짹7.7 msec, p=0.01). In contrast, DYSe was not changed according to the preload modification. These differences remained significant even after accounting for resting HR. DYSs and DYSe showed no correlation with basal HR (r=-0.17, p=0.32 for DYSs and r=-0.29, p=0.08 for DYSe, respectively). Conclusion The present study provides a novel insight on the possible relation of preload alteration to DYSs and DYSe. Given a significant impact of preload on DYSs, the loading status of each patient should be considered in assessing DYSs in order to aid in more efficient selection of patients for cardiac resynchronization therapy. In contrast, no consideration is required for estimating DYSe, although the significance of DYSe is yet determined. We also found that HR does not have to be considered for assessing DYSs and DYSe.