If you enter the study, in the cardiac catheterization lab, after the anesthesiologist has done his part (placed the breathing tube while you are asleep and obtained the x-ray), we will use the ultrasound to check the position of the breathing tube. To help us see the breathing tube better, we will put some fluid in the cuff ( the balloon at the tip of the breathing tube). The tube may be repositioned as needed based on the chest x-ray. The entire procedure is estimated to take no more than 10 minutes.