Inclusion Criteria:  Acute heart failure patient with reduced ejection fraction in Universitas Sebelas Maret Hospital with naive betablocker therapy Age >18 years old Initial Heart Rate > 50 bpm  Exclusion Criteria:  Cardiogenic Shock Septicaemia High degree AV Block or on pace maker History of beta blocker intolerance Reactive Pulmonary disease Severe Peripheral artery disease Creatinine level > 2.5 mg/dl Potassium serum >5 mmol/L