Usefulness of dobutamine echocardiography in distinguishing severe from nonsevere valvular aortic stenosis in patients with depressed left ventricular function and low transvalvular gradients

The safety of dobutamine echocardiography in coronary artery disease is well established.27 This study shows that dobutamine can be given safely to patients with AS during noninvasive hemodynamic monitoring. The small number of patients in this study preclude assessment of the effect of dobutamine echocardiography on outcome. A large prospective study is indicated. Although the continuity equation does not contain a flow-dependent constant, its limitations include underestimation of LV outflow diameter and failure to properly align the Doppler beam.18 However, even if errors in velocity measurement occurred, directional changes should be valid since the transducer locations were identical at baseline and dobutamine infusion.