Task: Answer Verification
Input (English): Question: Is systolic volume index by Doppler echocardiography an useful marker for stratification and prognostic evaluation in patients with severe aortic stenosis and preserved ejection fraction?
Answer: Patients with severe aortic stenosis, normal ejection fraction and low aortic flow have a worse prognosis. Analysis of aortic flow by Doppler echocardiography is useful in risk stratification and therapeutic decision-making in patients with aortic stenosis.
Output (English): yes