[Dobutamine doppler echocardiography in severe aortic stenosis with left ventricular dysfunction. Comparison with postoperative examination]. / Apport de l'échocardiographie Doppler sous dobutamine dans le rétrécissement aortique serré avec dysfonction ventriculaire gauche. Comparaison aux données postopératoires.

The association of left ventricular dysfunction with aortic stenosis worsens the spontaneous prognosis and increases operative mortality. The aim of this prospective study was to assess the predictive value of dobutamine Doppler echocardiography on the indices of left ventricular contractile function in patients with aortic stenosis and left ventricular dysfunction (LVEF < 0.45) undergoing aortic valve replacement. Eighteen patients, including 9 with coronary artery disease, were included in a protocol consisting of analysis of left ventricular function and of the severity of aortic stenosis before, during dobutamine infusion, and after valvular replacement. The dobutamine was given in progressive increments of 5 micrograms/Kg up to a maximum of 20 micrograms/Kg. During pharmacological stress, the functional aortic valve area increased from 0.46 +/- 0.15 to 0.56 +/- 0.23 cm2. Tolerance of the procedure was good. All but 2 patients improved their postoperative ejection fraction with values equivalent to those observed during the last increment of dobutamine (r = 0.73; p < 0.003). The patients with initial mean pressure gradients > 50 mmHg normalised their LVEF after valve replacement. The authors conclude that dobutamine echocardiography is useful for predicting the values of postoperative left ventricular contractile indices when severe aortic stenosis is associated with systolic dysfunction. It allows evaluation of the expected short term benefits to these indices after aortic valve replacement.