• Compare the hemodynamic parameters Cardiac Index (CI) and Pulmonary Capillary Wedge Pressure (PCWP) from baseline to 24 hours, between the two groups.
  

• Compare the efficacy and safety between the treatment groups, with regard to:
  
• • Changes in hemodynamic parameters from baseline to 24 and 48 hours.
  
• • Change in study subject’s and investigator’s assessment of symptoms of heart failure at 48 hours and 1-month follow-up.
  
• • Change in New York Heart Association (NYHA) classat 48 hours and 1-month follow-up.
  
• • Ability to continue treatment with β-receptor blocking agents.
  
• • Days alive and out of hospital during the 1-month follow-up period.
  
• • Change in B-type Natriuretic Polypeptide (BNP)at 24 and 48 hours and 1-month follow-up.
  
• • Proportion of treatment discontinuations and/or need for rescue therapy due to lack of efficacy.
  

Patients with decompensate heart failure (NYHA III-IV) and in need of intravenous inotrop support and who fulfil all inclusion and no exclusion criteria will be randomised into the study in proportion 1:1. Although stratification will be done so patients treated with beta-receptor blocker carvedilol will be divided the same between the study groups. All patients will receive infusions in parallell, one of the groups will receive active product (levosimendan or dobutamine) and the other will receive placebo (double-dummy technique). Catheterisation for measurement of hemodynamic parameters will be performed according to routine methods at the clinic. The measurements of the hemodynamic variables will start 30 minutes before start of study drug infusion and will be finished 48 hours after start of infusion. The most important variables during the measurements is Cardiac Index (CI)and Pulmonary Capillary Wedge Pressure (PCWP). Parallel registration will be done on ECG, blood pressure, blood frequency, central venous pressure, and lung artery pressure. Heart failure and other clinical symptoms will be registered continuously during 48 hours. Blood samples will be taken intermittent to record the blood values. Cogent rules for decreasing/increasing of the dose can be found in the study protocol, likewise rules for interruption or stoop for infusion.

Registration of side-effects will be done continuously. The recommendation for treatment for known side effects could be found in the protocol (section 5.3.4) and the protocol should be available during the study procedure. One month after the study the patients will be followed up with a very careful examination and also of the amount of visits and reason for visits to hospital during the past 30-35 days.