Materials and Methods After obtaining ethics committee approval and informed written consent of the patients, this study will be conducted in 60 adult patients with valvular heart disease and coronary artery disease of New York Heart Association class II-III aged 18 to 60 years undergoing elective cardiac surgery. All patients will receive their usual cardiovascular medications except angiotensin - converting enzyme inhibitors, digoxin and diuretics on the morning of surgery as per our institutional practice. On arrival inside operating room and after securing peripheral venous access with 16 G catheter, continuous monitoring will be instituted that will include 5-lead electrocardiogram, pulse oximetry, end-tidal capnometry, and invasive arterial blood pressure through a 20-G catheter inserted in a radial artery. A central venous catheter will be inserted before induction of anaesthesia under local anaesthesia and mild sedation with midazolam 0.04mg/kg body weight.