Inclusion Criteria:  Male or female patients ≥ 18 years old Written informed consent from patient Patients are in sinus rhythm Oral Betablocker in the patients long-term medication  One of the following cardiac surgical procedures which is planned on cardiopulmonary bypass (CPB):  Single valve surgery Single or multiple CABG procedures Single valve surgery in combination with one or multiple coronary artery bypass grafts (CABGs) Multiple valve surgery in combination with or without CABG Single or multiple valve surgery in combination with ascending aorta procedure with or without additional CABG Re-surgery of aortic valve, mitral valve, aortic arch or ascending aorta with or without CABG Cardiac surgery is performed electively  Exclusion Criteria:  Bodyweight > 101kg and/or BMI ≥ 40 Cardiac surgery is planned as minimally invasive procedure (e.g., without thoracotomy or with lateral incision, minimal thoracotomy) or planned as off-pump surgery Planned maze procedure, radiofrequency ablation, pulmonary vein ablation, resection of the atrial appendix or atrial resections during the surgery Sinus bradycardia (resting heart rate < 50/min) at screening and before start of IMP treatment Second- or third-degree atrioventricular block at screening and before start of IMP treatment Clinical hypothyroidism or hyperthyroidism at screening History of ventricular arrhythmia Permanent atrial fibrillation or atrial fibrillation at time of screening and IMP administration Emergency cardiac surgery Requiring inotropic, vasopressor or requiring ventilatory support at time of screening Circulatory shock requiring mechanical circulatory support before initiation of study medication Distributive shock (cardiac index>2.2 L/min with norepinephrine dose > 0.3 µg/kg/min to reach mean arterial pressure > 65mmHg) before initiation of study medication More than 5 units of RBC necessary to maintain a haemoglobin level >8mg/dl at the end of surgery Prior cardiac surgery within the past 6 months History of heart transplantation or planned heart transplantation  Any other disease or condition that is likely to interfere with the evaluation of the study drug, outcome assessment or satisfactory conduct of the study:  Active infective endocarditis Stroke or transient ischemic attack (TIA) within the last 6 months Concomitant disease with a life expectancy of less than 6 months Cardiopulmonary resuscitation within the last 4 weeks Patients requiring renal replacement therapy Active infection on current systemic antibiotics and/ or temperature greater than 38°C at time of screening and before start of surgery Haemoglobin < 5 mmol/l (< 8.06 g/dl) Any systemic anti-cancer therapy within past 3 months Patients with known hypersensitivity to any constituent of the IMP  General exclusion criteria:  Pregnant (in women of childbearing potential a urine or blood pregnancy test has to be performed) or breast-feeding women. Women with childbearing potential (defined as within two years of their last menstruation) not willing to practice appropriate contraceptive measures (e.g., implanon, injections, oral contraceptives, intrauterine devices, partner with vasectomy, abstinence) while participating in the trial Participation in any interventional clinical trial within the last one-month prior randomization in this clinicaltrial (screening failures can be rescreened, if appropriate) Alcohol, drug, or medication abuse Employee at the study site, spouse/partner or relative of any study staff (e.g., investigator, subinvestigators, or study nurse) or relationship to the sponsor