Cardiac ablation is a therapeutic procedure in which abnormal tissues of the heart's electrical conduction system are destroyed, or ablated, in an effort to restore a consistently normal heart rhythm. The procedure most commonly involves threading a long tube, or catheter, through a blood vessel in the leg to the heart to carry out the ablation. Potential risks accompany a cardiac ablation procedure, although most patients are successfully treated without major complications.
Worsening or New Arrhythmia
Cardiac ablation can sometimes lead to a worsening or new heart rhythm abnormality, also known as an arrhythmia. The most concerning arrhythmia is AV heart block in which the electrical signals from the upper part of the heart fail to reach the lower heart. This condition can compromise the heart's ability to pump a sufficient volume of blood to meet the body's needs. In a 2007 study of more than 5,300 patients undergoing cardiac ablation published in the "Canadian Journal of Cardiology," Dr. Gilles O’Hara and colleagues report that less than one percent of patients developed AV heart block with the procedure. When this complication does occur, AV heart block often requires implantation of a permanent pacemaker to control the heart rhythm.
Blood Vessel Damage
A rare complication of cardiac ablation is damage to one or more of the blood vessels along the route of the catheter, notes the National Heart, Lung and Blood Institute. Blood vessels scraped by the catheter may weaken and possibly burst. Although exceedingly uncommon, the catheter may poke through the wall of a blood vessel. These rare complications of cardiac ablation often require emergency medical treatment to repair the damaged vessels.
Blood Clots
A cardiac ablation procedure may trigger the formation of blood clots, which can lead to serious complications such as a stroke or heart attack. In a hallmark 1999 study of 1,050 patients undergoing cardiac ablation published in journal "Circulation," Dr. Hugh Calkins and colleagues report two procedure-related strokes and one heart attack occurred. Patients with serious preexisting heart disease are at highest risk for a procedure-related heart attack.
Cardiac Tamponade
The heart rests within a tissue enclosure called the pericardial sac, which minimizes friction between the beating heart and nearby structures. Cardiac ablation may provoke an abnormal accumulation of fluid in the pericardial sac, a condition known as cardiac tamponade. The excess fluid restricts heart muscle movement and reduces the area available within the heart chambers to collect blood, thereby reducing the volume of blood pumped to the body. Cardiac tamponade is a medical emergency requiring immediate treatment to relieve the external pressure on the heart. In the 2007 study conducted by O'Hara and colleagues, one patient out of 5,330 developed cardiac tamponade after a catheter ablation procedure.
References
- American Heart Association: Heart Block
- "Canadian Journal of Cardiology"; Catheter Ablation for Cardiac Arrhythmias: A 14-year Experience with 5330 Consecutive Patients at the Quebec Heart Institute, Laval Hospital; Gilles E. O’Hara, M.D., et al.; October 2007
- "Circulation"; Catheter Ablation of Accessory Pathways, Atrioventricular Nodal Reentrant Tachycardia, and the Atrioventricular Junction Final Results of a Prospective, Multicenter Clinical Trial; Hugh Calkins, M.D., et al.; 1999
- National Heart, Lung and Blood Institute: Catheter Ablation
- American Heart Association: Radiofrequency Ablation
