Right ventricular (RV) dysfunction frequently complicates advanced left ventricular heart failure and contributes to an unfavorable prognosis. Levosimendan is a novel inodilator that beneficially affects hemodynamics and left ventricular systolic and diastolic function in patients with advanced heart failure. However, its effects on RV function have not yet been properly assessed in these patients. In this randomized trial, the impact of levosimendan or placebo on various echocardiographic parameters of RV systolic and diastolic function was investigated in 54 patients with advanced heart failure due to left ventricular systolic dysfunction. Tissue Doppler imaging maximal systolic tricuspid annular velocity (S wave) increased significantly only in the levosimendan group (8.2 +/- 3.2 vs 9.0 +/- 3.0 cm/s, p <0.03). Tissue Doppler imaging RV early diastolic velocity (E wave) and the ratio of early to late diastolic velocities (E/A) also increased significantly after levosimendan administration (p <0.01 and p <0.05, respectively). Systolic pulmonary arterial pressure decreased significantly (54 +/- 11 vs 43 +/- 11 mm Hg, p <0.01) in the levosimendan-treated patients. Levosimendan beneficially modulated neurohormonal and inflammatory status by decreasing B-type natriuretic peptide levels (p <0.05) and by altering the ratio of interleukin-6 to interleukin-10 in favor of the latter (p <0.05). In conclusion, levosimendan could offer further therapeutic advantages in patients with advanced heart failure by improving systolic and diastolic RV function.