Cardiac ablation, or cardiac catheter ablation, is a procedure to treat rhythm disturbances of the heart. Catheter ablation is used when a rhythm disturbance, called arrhythmia, is not controlled by medications or when medications cause too many side effects. The procedure is performed by placing small catheters inside the heart, mapping out the rhythm and, using a long tube with an electrode at the tip, applying radiofrequency energy to destroy, or ablate, the abnormal tissue causing the rhythm disturbance. The American Heart Associate states that radiofrequency cardiac ablation has more than a 90 percent success rate in controlling rhythm disturbances. The risk of complications is low; however, there are some contraindications associated with cardiac ablation.
Intracardiac Blood Clot
Cardiac arrhythmias can cause uncoordinated pumping of the heart which predisposes the heart to forming clots inside the cardiac chambers. The presence of intracardiac blood clots is a contraindication to catheter ablation, according to a May 2006 article published in "Heart Rhythm." For proper positioning of the ablation catheter, there is significant manipulation of the catheter within the cardiac chambers. If a blood clot is present, it can break up and be pumped out of the heart causing a stroke, heart attack or other complication.
Artificial Heart Valves
When a heart valve fails, it is either repaired or replaced with an artificial valve. Having an artificial valve, as reported in PatientPlus, particularly a metal valve, is a contraindication in most patients to catheter ablation. Proper positioning of the catheter may require traversing a valve with the catheter. Crossing an artificial valve is technically very difficult and may cause damage to the catheter or the valve.
Anticoagulation
There is a significant risk of clot formation both during the catheter ablation, as well as after the procedure, according to the "Heart Rhythm" article. Anticoagulation with heparin, Coumadin, or other anti-clotting drugs is usually given during the procedure and continued for two months. Patients who cannot be anticoagulated because of bleeding problems or other reasons should not be considered for ablation therapy.
