['The effects of midazolam and propofol on left ventricular (LV) diastolic function have not been evaluated in humans. We tested the hypothesis that midazolam and propofol alter LV diastolic function evaluated with transmitral and tissue Doppler transthoracic echocardiography in patients with normal LV systolic function in the presence and absence of preexisting diastolic dysfunction. After IRB approval and informed consent, patients (n = 34) with normal or reversed transmitral blood flow velocity E-to-A ratios received 3 escalating doses of midazolam (0.025, 0.05, and 0.1 mg/kg) or propofol (0.25, 0.5, and 1.0 mg/kg) over 10 s at 5-min intervals. Hemodynamic variables and indices of diastolic function were recorded 3 min after each dose of midazolam and propofol. Patients with diastolic dysfunction demonstrated decreased ratios of peak transmitral E-to-A wave velocity and their corresponding time-velocity integrals as compared with normal patients. Reductions in anterior and posterior mitral annulus E/A ratios were also present. Midazolam and propofol did not further alter indices of LV diastolic function in patients with impaired early LV filling. The results indicate that sedation with midazolam or propofol does not affect indices of LV diastolic performance in healthy patients and those with preexisting diastolic dysfunction.'] Does conscious sedation with midazolam or propofol alter left ventricular diastolic performance in patients with preexisting diastolic dysfunction : a transmitral and tissue Doppler transthoracic echocardiography study?