The risks of cardiac catheterization, or "cath," are allergies to the contrast medication, tape sensitivity, and infection. Pain, bruising, or heavy bleeding at the site of the catheter’s entry might also occur. Blood clotting, heart attack, and pericardial effusion are possible risks, and latex allergy or kidney damage will affect a small number of patients. Alternately, the catheter could damage the heart or the blood vessels, cause arrhythmias, or result in death. There is minimal likelihood of serious or fatal reactions to this common procedure, but complications are more likely in much older patients, those who are extremely ill, diabetics, or individuals undergoing catheterized heart repairs.
Generally, if patients experience any of the risks of cardiac catheterization, they will have minor symptoms. For instance, many individuals develop a slight fever about a day after being exposed to contrast dye. The area where the cath was inserted may feel painful or swollen, too, and sometimes people need extra pressure dressings because the insertion site may continue to bleed. A few individuals also discover they have tape sensitivity and develop rashes from the pressure dressing or the tape used during the procedure.
Additional risks of cardiac catheterization can be minor or major. While tape sensitivity usually means a rash, latex allergy can be quite serious, given the amount of latex exposure associated with most hospitalizations. A minor reaction to dye tends not to be problematic, but a serious allergy to contrast dye can cause a severe systemic reaction. Diabetics may react extremely poorly to contrast material, causing the kidneys to shut down and necessitating dialysis. Infections are another risk that can vary in severity; a small infection is easily handled with antibiotics, but a major blood infection with an antibiotic resistant strain of bacteria is much harder to treat.
There are risks of cardiac catheterization that are always serious, however. Sometimes a cath induces repeated arrythmias and damages the electrical pathways of the heart. Blood clots can form that may cause strokes, pulmonary emboli, or heart attacks.
A type of bruising and fluid retention, called a pericardial effusion, may also build in the sack surrounding the heart, which can inhibit its function and require drainage. Even in non-diabetics, the kidneys can become overloaded and damaged, and any patient undergoing a cath may be at risk for damage to blood vessels or the heart’s structures. Death can occur during this procedure, too, though this is estimated to occur in only about 0.1% of patients.
If cardiac catheterization is used to repair heart defects or treat narrowed blood vessels, risk for adverse reactions tends to increase. On the other hand, repairs of this type are still less dangerous than open-heart surgeries to address cardiovascular problems. They have the advantages of being performed without general anesthesia, in many cases, and they may be less likely to cause infection. An entire specialty called interventional cardiology has arisen in the last few decades, and continues to develop new ways to treat cardiac problems with catheterization, to avoid the more risky open-heart surgery.
Selecting patients carefully is an important part of reducing the risks of cardiac catheterization. Doctors must consider a patient’s present health, age, and medical history. Sometimes they will determine that patients with an elevated likelihood for complications are better off not receiving a cardiac cath.