I assume that since they are talking about a catheterization, that they believe some of the blood vessels are blocked, instead of the problem being a leaking heart valve or something else. A catheterization is how they determine how much blockage there is in the arteries around the heart. From what I understand, the catheter is run through the blood vessels to the heart to insert dye to make images of the blood vessels easier to see. If there is severe blockage, there will not be enough blood flowing (oxygen) to the heart muscle. This could lead to a heart attack if untreated. If they find blockage, the treatment depends on how many arteries are blocked and how severely the blood flow through these arteries is restricted. Less severe cases may be treated with drugs designed to dissolve the blockage. Blood thinning drugs will also help to increase blood flow. Next in treatments would be a “stint”. This stint is inserted into the blood vessel to hold the restricted area open. More severe cases would require heart surgery. With this, the doctors would take a section of vein, usually from the leg, and they will use it to by-pass the blockage on the heart. My dad had by-pass surgery in 1977, and again in the early 1990’s. This procedure has improved much over the years! Many people after heart surgery go on to live many more years. I hope this helps you understand, and I hope things turn out well for your mother. I will stop and say a prayer for her!