The objective of this trial to see whether:

-Cardiac performance (cardiac index and secondary outcomes)can be improved in patients with acute heart failure (AHF) and symptoms and consequences of fluid overload (pulmonary and interstitial edema) and poor peripheral perfusion can be reduced by:

1. Providing lactate as a substrate(Improve cardiac index)
2. Simultaneously restoring optimal preload

Optimal standard treatment will be achieved in both arms with the use of current best treatment protocol for AHF as per independent treating physician.

4. To assess effects of 0.5M Na lactate (Totilac) on plasma and urine biological parameters (sodium, potassium, chloride, pH, bicarb, base excess, albumin)

5. To assess effects of 0.5M Na lactate on morbidity and mortality.

• Acute heart failure is a critical illness for which current treatments are suboptimal.
• The various symptoms are related to inadequate cardiac output and usually include left ventricular overload with pulmonary oedema, interstitial fluid accumulation and tissue oedema (as indicated by frequent hyponatremia and hypoalbuminemia) and insufficient peripheral perfusion frequently manifesting as cold extremities and low urine output.
• The current treatment of this syndrome is based on diuretics, vasodilators and/or inotropes, but fluid administration is also required to optimise the intravascular volume state and to reverse shock if present. Therefore management of body fluid balance remains a challenge since treatment aims to simultaneously maintain or improve intravascular volume and decrease body fluid excess and oedema.
• The purpose of the present study is to assess in a prospective randomised trial the efficacy and safety of a newly designed crystalloid solution, 0.5 M sodium lactate, with properties potentially able to improve multiple pathophysiological aspects of AHF, as compared to the use of standard crystalloid solution Compound Sodium Lactate (mildly hypoosmolar ~ 274 mOsm/L and isotonic).

Inclusion Criteria:

• Age: more than 18 years
• Heart failure criteria:

Left heart failure: as evidenced by 2 out of 3:

• Left ventricular ejection fraction (LVEF) ≤ 40% and cardiac index ≤ 2.5 L/min/m2
• Acute pulmonary oedema of cardiac origin or mechanical ventilation (including CPAP/BIPAP) for respiratory failure of predominantly cardiac origin
• Need for inotropes/vasopressors for cardiac pump failure OR

Right heart failure: as evidenced by 1 out of 2:

• Bilateral leg oedema above ankles
• RV failure (low tricuspid annular plane systolic excursion (TAPSE), dilated floppy RV)
• Poor peripheral perfusion as evidenced by 2 out of 3:

Cold mottled skin Low urine output Acutely clouded sensorium/poor mentation

• Consent obtained from patient or patient's next of kin.

Exclusion Criteria:

• Hypernatremia: [Na] >145 mmol/L
• Diagnosed hypertrophic obstructive cardiomyopathy
• Uncorrected severe valvular heart disease
• Documented third degree heart block, sustained ventricular tachycardia
• Documented cardiac tamponade
• Septic shock
• Acute respiratory distress syndrome (ARDS)
• Moribund patients likely to die before 24h
• Patients with major diseases of limited prognosis such as end stage cancer,end-stage liver failure, end stage dialysis dependent renal failure
• Patients with absolute indication for acute hemodialysis/hemofiltration (pH, K, urea > 35 mmol/L, severe fluid overload in the presence of oliguria < 200 mL/6h.
• Known pregnancy