Some of the following tests may be carried out (either at a pre-admission clinic or on the day of admission.) Chest X-ray - this will look at the size and shape of the heart and the general condition of your lungs. Electrocardiogram (ECG) - this shows the electrical activity of the heart and is routine for anyone undergoing an anaesthetic. Blood tests - a blood sample is taken from your arm and various tests are carried out including your blood group. Pulmonary Function Tests - these are breathing tests which measure how well your lungs are working so that your anaesthetic and operation can be performed as safely as possible. CT Scan (CAT scan) - this is a type of X-ray. A number of pictures are taken and fed into a computer to form a detailed picture of the inside of the body. Barium Swallow - you will be asked to swallow a solution containing barium. Using an X- ray machine, the doctor will then watch the barium flow down the oesophagus. X-ray pictures can also be taken at the same time. Click here for Oesophagectomy and Gastrectomy.