Objective: We sought to study diastolic function in patients with low-flow/low-gradient aortic stenosis (LF/LGAS) and to clarify the relationship between contractile reserve on dobutamine stress echocardiography (DSE) and the restrictive filling pattern on echocardiography in patients with LF/LGAS. Patients and Methods: Thirty patients with LF/LG severe AS were divided into 2 groups. Group I included 14 patients with contractile reserve on DSE. Group II included 16 patients with no contractile reserve on DSE. Diastolic function was studied in all patients using baseline echo Doppler study. Results: No significant difference was found between both groups regarding baseline left ventriculae end-diastolic dimension (LVEDD), ejection fraction (EF), stroke volume, aortic valve area (AVA), mean transaortic pressure gradient, septal thickness or posterior wall thickness, P > 0.05. Transmitral E/A ratio was 1.3
0.5 compared to 2.6
0.7, respectively, deceleration time (DT) was 160
31 compared to 120
15 ms, isovolumic relaxation time (IVRT) was 81
22 compared to 53
18 ms, S/D ratio was 1.2
0.3 compared to 0.8
0.2, respectively, (P < 0.001 for all).Three patients in group I had restrictive pattern of diastolic dysfunction compared to 12 in group II (P < 0.003). DSE data in both groups showed a peak SV of 64
11 mL compared to 50
7 mL (P < 0.005), peak EF was 42
9 compared to 34
11% (P < 0.03). Peak stress mean transaortic pressure gradient was 39
9 compared to 22
10 mmHg, respectively, P < 001. Conclusion: Restrictive filling pattern of diastolic dysfunction on baseline echo Doppler study may predict lack of contractile reserve in patients with LF/LG severe AS. (Echocardiography 2014;00:1–6)