【Objective】 The aim of this study was to assess the relationship between left ventricular diastolic function and forearm endothelial function in the patients with erectile dysfunction (ED) without overt cardiovascular disease. 【Methods】 We prospectively evaluated 30 patients (mean age 30.4 ± 4.3 years) and 33 control subjects (mean age 29.8 ± 3.9 years). LV function was assessed by classical methods and Doppler tissue imaging (DTI). Left ventricular ejection fraction (EF)

peak early (E) and late (A) transmitral filling velocities

their ratio (E/A)

LV isovolumetric relaxation time (IVRT)

LV isovolumetric contract time (IVCT) and Tei index were evaluated by conventional echocardiography. Early diastolic (E′)

late diastolic (A′)

Myocardial performance index (MPI)

isovolumic contraction time (IVCT′)

isovolumic relaxation time (IVRT′)

the time interval difference of isovolumic relaxation (TIVRT-IVRT′) and the ratio of early diastolic mitral inflow velocity to E′ (E/E′) were obtained by tissue Doppler imaging (TDI).Endothelial function

measured as flow-mediated dilatation of the brachial artery using ultrasound

was calculated in the subjects. 【Results】 Endothelium dependent vasodilation(8.5% ± 2.79% vs 13.4% ± 2.5%

P < 0.001) was impaired in the ED group than that in the control group. And the Tei index (0.55 ± 0.08 vs 0.41 ± 0.06

P < 0.001) was larger than in the control group. IVRT(85.5 ± 13.4 ms vs 61.7 ± 8.4 ms

P < 0.001)was prolonged in the ED group compared with the control group. IVRT

Tei index and TIVRT-IVRT′ were significantly related to endothelium-dependent vasodilation by bivariate analysis. 【Conclusions】 It was found that endothelial function and left ventricular diastolic function were impaired in ED patients. Left ventricular diastolic function parameters

IVRT

Tei index and TIVRT-IVRT′ was related to endothelium-dependent vasodilation in patients with ED without overt cardiovascular disease.