Background. Diagnosis and management of paradoxical low-flow aortic stenosis (PLF-AS) is challenging in clinical practice. In addition, its pathophysiology has not been fully understood. We hypothesized that left ventricular (LV) myocardial function is deteriorated in PLF-AS and it is closely related to global afterload on LV. Methods. Echocardiographic data, including 2D-strain, of sixty severe AS [(aortic valve area (AVA)<1.0cm2] patients with normal LV ejection fraction were prospectively collected. Results. Among 60 patients, 11 patients were classified as PLF-AS. Compared with normal flow AS patients, PLF-AS patients were more likely to have worse global longitudinal strain (GLS) (-12.3짹4.4% vs. -18.2짹3.5%, p-value<0.01), lower AVA (0.51짹0.15cm2 vs. 0.73짹0.17cm2, p-value<0.001) and higher valvuloarterial impedance (5.87짹1.12mmHg•m2/mL vs. 3.68짹0.76mmHg•m2/mL, p-value<0.01). GLS showed significant negative linear correlationship with SVi (r=-0.365) and positive correlationship with E/E��� and LV mass index (r=0.459 for E/E���, r=0.393 mass index). Only valvuloarterial impedance was the significant determinant of myocardial performance. Conclusions. Global longitudinal strain is depressed in PLF-AS patients. This implies that subclinical myocardial dysfunction is evident and may be related to poor clinical outcome in these patients. It also suggests the possible prognostic and diagnostic value of 2D strain in PLF-AS. In addition, global LV afterload is an important determinant of myocardial dysfunction in severe AS patients.