This is ordinarily not painful. The anesthesiologist will administer the anesthetic, which will bring deep sleep, freedom from pain, and absence of memory of the operation. During surgery a heart-lung bypass machine will take over the normal functions of your heart and lungs allowing the surgeon to replace or repair your heart valve. After surgery, the staff will take you to an intensive care unit or recovery room. While you are in this area you will be monitored constantly by a highly trained staff.
Anesthetics wear off at different rates.
Some people respond in an hour or two but most people take longer. You may be able to hear or open your eyes before you can move your arms and legs. Soon your mind and body will be fully responsive. When you awaken, you may find you have a tube in your mouth that is preventing you from talking. This is a breathing tube connected to a respirator.