You don t say how long ago his heart surgery was. If it was within the past week, some patients will have local swelling of the lips, perhaps from mild trauma or irritation from the endotracheal tube being in the mouth or moving around a little or sometimes the patient biting on the tube and/or his lip while sedated or unconscious. That should subside naturally over the course of a week. It is also possible he might be allergic to latex, a component of the tape glue that is usually used to secure the tube during intubation to prevent it from moving around or inadvertently coming out. That usually subsides when the tube and tape are removed. If the tube have been out awhile without improvement, or if the lip swelling is continuing past a week or so, then his doctors should review his medication list for drugs that he might be allergic to. A common cause of lip swelling are drugs in the ACE Inhibitor class, such as Captopril, Lisinopril, Benazepril. Withdrawing or stopping these blood pressure or heart failure drugs usually will cause the lip swelling to stop fairly quickly. Good luck, and let us know what happens from here.