DOBUTAMINE AND NITROPRUSSIDE INFUSION IN PATIENTS WITH SEVERE CONGESTIVE-HEART-FAILURE - HEMODYNAMIC IMPROVEMENT BY DISCORDANT EFFECTS ON MITRAL REGURGITATION, LEFT ATRIAL FUNCTION, AND VENTRICULAR-FUNCTION

Objectives In patients with severe heart failure additional therapeuti c support with intravenous inotropic or vasodilator drugs is frequentl y used in the attempt to obtain hemodynamic control. The nature and ex tent to which diastolic filling, atrial function, and mitral regurgita tion are modified by these drugs have not been fully explored. The aim of this study was to compare the acute adaptations of the left ventri cular performance, left atrial function, and mitral regurgitation that accompanied hemodynamic improvement during intravenous dobutamine and nitroprusside infusions in patients with severe chronic heart Failure . Methods Ferry consecutive patients with severe heart failure were ev aluated by simultaneous echo-Doppler and hemodynamic investigations at baseline and during nitroprusside and dobutamine administration. Mitr al Flow velocity variables, left atrial and ventricular volumes, left atrial reservoir, conduit and pump volumes, and mitral regurgitation j et area were compared by analysis of variance For repeated measurement s. Results Nitroprusside increased cardiac output (2.1 +/- .5 vs 2.6 /- .5 L/min/m(2), p < 0.004), reduced left ventricular filling pressur e (25 +/- 6 vs 14 +/- 4 mm Hg, p < 0.0001), and improved left atrial p ump volume (19 +/- 3 vs 26 +/- 12 ml, p < 0.02) without variations in left atrial reservoir and conduit volume. The restoration of preload r eserve and improvement of the atrial contribution to left ventricular diastolic filling were demonstrated by the Doppler mitral flow pattern , which moved from a restrictive to a normal pattern. Furthermore mitr al regurgitation decreased in all patients (9 +/- 4.6 vs 4.6 +/- 3.4 c m(2), p < 0.0001). Dobutamine increased cardiac output (2.1 +/- .5 vs 2.8 +/- .6 L/min/m(2)), but the effects on pulmonary wedge pressure an d mitral regurgitation were variable and unpredictable. Left atrial re servoir and conduit volumes increased, whereas left atrial pump volume did not change (19 +/- 13 vs 22 +/- 14 ml, p = NS). Furthermore Doppl er mitral flow showed a persistent restrictive pattern. Conclusions In patients with advanced congestive heart failure both nitroprusside an d dobutamine improve cardiac output, with different adaptations of lef t ventricular performance and left atrial function. Nitroprusside seem s to restore both atrial and ventricular pump function better. Careful echo-Doppler monitoring during drug infusion provides information rel evant to the clinical treatment of individual patients.