Additive effects of dobutamine and amrinone on myocardial contractility and ventricular performance in patients with severe heart failure.

Abstract

The effects of amrinone, dobutamine, and a combination of the two drugs on peak positive left ventricular dP/dt and left ventricular performance were evaluated in 11 patients with chronic congestive heart failure. When administered alone, both dobutamine (10.9 gg/kg/min) and intravenous amrinone (1.9 mg/kg/min) significantly increased left ventricular dP/dt and performance. When compared with dobutamine alone, the addition of amrinone resulted in further increases in left ventricular dP/dt and cardiac index (to 1319 ± 419 from 1202 ± 376 mm Hg/sec, p < .002, and to 3.56 ± 0.78 from 3.04 ± 0.67 liters/min/m2, p < .01, respectively). The combination also induced a further reduction in left ventricular end-diastolic pressure (to 15.3 ± 11.3 from 18.2 ± 10.3 mm Hg, p < .05) when compared with amrinone alone. The combination of dobutamine and amrinone increased heart rate slightly when compared with either drug alone, but did not further reduce systemic arterial pressure when compared with amrinone alone. The dose-response curve of left ventricular dP/dt and performance during titration of dobutamine with and without the addition of intravenous amrinone was evaluated in seven patients. The addition of amrinone to any dose of dobutamine produced higher cardiac index and lower systemic vascular resistance than dobutamine or amrinone alone. Thus, when compared with dobutamine alone in patients with chronic congestive heart failure, the addition of intravenous amrinone to dobutamine results in an additive improvement in left ventricular performance throughout the dose range. Circulation 74, No. 2, 367-373, 1986. DOBUTAMINE is a synthetic catecholamine that directly stimulates myocardial /,-adrenergic receptors.It has been used extensively to improve myocardial contractility and ventricular performance in patients with acute left ventricular dysfunction or decompensated congestive heart failure.", 2 Dobutamine is usually well tolerated. Through its effects on cardiac mechanics and hemodynamics, it has the potential to alter myocardial oxygen utilization (MVO2) in several different ways. By increasing contractility and heart rate, it may increase MVO2, but the simultaneous reduction in wall tension tends to lower oxygen use. In some situations the stimulation of contractility and heart rate may outweigh the reduction in wall tension to

Intracoronary infusion of dobutamine to patients with and without severe congestive heart failure. Dose-response relationships, correlation with circulating catecholamines, and effect of phosphodiesterase inhibition.

“…Only one other study has addressed this important issue in vivo in patients with CHF (35). Our data and conclusion are consistent with those of Gage et al (35) who showed that the +dP/dt response to intravenous dobutamine was greater in the presence of intravenous amrinone. In addition, the IC infusion method allows two further conclusions.…”

“…Likewise, the positive inotropic response of guinea pig papillary muscle to isoproterenol is potentiated when isoproterenol is given at the peak of a minimally effective concentration of milrinone or after prolonged incubation with milrinone (34). Only one other study has addressed this important issue in vivo in patients with CHF (35). Our data and conclusion are consistent with those of Gage et al (35) who showed that the +dP/dt response to intravenous dobutamine was greater in the presence of intravenous amrinone.…”

“…Second, due to the design of our study, the further improvement in left ventricular pump function caused by IC dobutamine following IC milrinone, as reflected by the relationship between stroke work index and left ventricular end-diastolic pressure, can be attributed entirely to the direct actions of the two agents on myocardial systolic and/or diastolic (36) function. Although Gage et al (35) demonstrated that the +dP/dt response to dobutamine was greater in the presence of intravenously administered amrinone, the actual contribution of this positive inotropic action to the overall hemodynamic effect of the combination of systemic dobutamine and amrinone could not be determined, since systemic amrinone also exerts a substantial vasodilator action which, in and of itself, could cause a significant hemodynamic improvement (37).…”

The Role of Enoximone in the Treatment of Cardiogenic Shock

“…Gage et al [14] demonstrated that amrinone and dobutamine had additive effects on left ventricular function in patients with congestive heart failure. Similar observations were made with other phosphodiesterase inhibitors [15].…”

Inotrópicos, não devem ser prescritos?

“…Se não há muitas dúvidas sobre seu valor na terapêuti-ca dos quadros descompensados [1][2][3][4][5] , o mesmo não ocorre quando da sua prescrição de maneira crônica para pacientes compensados [6][7][8][9] . A sua prescrição, quando e como, vem sendo objeto de vários artigos e é motivo de intensa controvérsia, o que nos induziu a expor nosso ponto de vista sobre tema tão importante.…”