Catheter Ablation of Supraventricular Arrhythmias and Atrial FibrillationADAM R. SHAPIRA, MD, Advanced Heart Care PA, The Heart Hospital Baylor Plano, Plano, Texas Supraventricular arrhythmias, a fam-ily of cardiac arrhythmias includ-ing supraventricular tachycardias and atrial flutter, are common, often persistent, and rarely life threaten-ing. They arise from the sinus node, atrial tissue, or junctional sites between the atria and ventricles, and are amenable to medi-cal and catheter-based therapies. The term “supraventricular tachycardia” commonly refers to atrial tachycardia, atrioventricular nodal reentrant tachycardia (AVNRT), and atrioventricular reciprocating tachycar-dia (AVRT). Atrial fibrillation is a distinct entity classified separately. Although antiarrhythmic medications can be used for treatment, they often lack effec-tiveness, are associated with multiple adverse effects, and are prone to drug-drug interac-tions. Thus, a principal therapy for many supraventricular arrhythmias is catheter- based ablation. Ablation can safely treat, if not cure, many common dysrhythmias, with excellent effectiveness (Table 11-26) and without incurring the long-term, sometimes morbid, consequences of antiarrhythmic drug therapy. Catheter ablation is first-line therapy for many supraventricular arrhyth-mias, including AV NRT, symptomatic AV RT, atrial flutter, and symptomatic or incessant atrial tachycardia.1 Catheter-based ablation of a cardiac arrhythmia is performed in an electrophysi-ology laboratory in conjunction with an electrophysiology study. An electrophysiol-ogy study involves the percutaneous inser-tion of catheters into the femoral veins and often the internal jugular vein. The catheter tips are positioned at specific locations in the heart. Electrical stimulation is delivered to the myocardium via these catheters to char-acterize cardiac conduction and arrhyth-mias. Once the patient’s conduction system has been studied and the rhythm distur-bance diagnosed, an ablation catheter is used to thermally destroy the pathogenic myo-cardial tissue underlying the arrhythmia’s initiation or maintenance. Success and com-plication rates vary, depending on the indi-vidual arrhythmia (Table 11-26). Introduction of catheters into the heart, with or without the delivery of ablative energy, uniformly Supraventricular arrhythmias are relatively common, often persistent, and rarely life-threatening cardiac rhythm disturbances that arise from the sinus node, atrial tissue, or junctional sites between the atria and ventricles. The term “supraventricular arrhythmia” most often is used to refer to supraventricular tachycardias and atrial flutter. The term “supraventricular tachycardia” commonly refers to atrial tachycardia, atrioventricular nodal reentrant tachycardia, and atrioventricular reciprocating tachycardia, an entity that includes Wolff-Parkinson-White syndrome. Atrial fibrillation is a distinct entity classified separately. Depending on the arrhythmia, catheter ablation is a treatment option at initial diagnosis, when symptoms develop, or if medical therapy fails. Catheter ablation of supraventricular tachycardias, atrial flutter, and atrial fibrillation offers patients high effectiveness rates, durable (and often perma-nent) therapeutic end points, and low complication rates. Catheter ablation effectiveness rates exceed 88 percent for atrioventricular nodal reentrant tachycardia, atrioventricular reciprocating tachycardia, and atrial flutter; are greater than 86 percent for atrial tachycardia; and range from 60 to 80 percent for atrial fibrillation. Complication rates for supraventricular tachycardias and atrial flutter ablation are 0 to 8 percent. The complication rates for atrial fibrillation ablation range from 6 to 10 percent. Complications associated with catheter ablation result from radiation exposure, vascular access (e.g., hematomas, cardiac perforation with tamponade), catheter manipulation (e.g., cardiac perfo-ration with tamponade, thromboembolic events), or ablation energy delivery (e.g., atrioventricular nodal block). (Am Fam Physician. 2009;80(10):1089-1094, 1095. Copyright © 2009 American Academy of Family Physicians.)T Patient information: A handout on supra-ventricular tachycardia, written by the author of this article, is provided on page 1095. This article exempi-fies the AAFP 2009 Annual Clinical Focus on manage-ment of chronic illness.Downloaded from the American Family Physician Web site at www.aafp.org/afp. Copyright © 2009 American Academy of Family Physicians. For the private, noncommercial use of one individual user of the Web site. All other rights reserved. Contact [email protected] for copyright questions and/or permission requests.1090 American Family Physician www.aafp.org/afp Volume 80, Number 10 V November 15, 2009carries the risk of cardiac perforation and possibly tam-ponade. If detected early and in the absence of systemic anticoagulation, iatrogenic cardiac tamponade caused by catheter perforation uncommonly is a life-threatening complication; however, it does require the percutaneous insertion of a temporary subxiphoid pericardial drain if associated with hemodynamic compromise.Atrial Tachycardia Sustained atrial tachycardia is a relatively uncommon arrhythmia diagnosed in about 5 to 15 percent of patients referred for supraventricular tachycardia ablation, but with increasing age, it constitutes a larger percentage of supraventricular tachycardias.27 It is a focal arrhythmia that can arise from anywhere in the right or left atrium. For atrial tachycardia ablation, success rates are 86 to 100 percent, with a recurrence rate of 0 to 8 percent.1-3 Uncommon complications (0 to 8 percent) include car-diac perforation, phrenic nerve injury, and atrioventricu-lar or sinus node dysfunction.1 Catheter ablation of atrial tachycardia is reserved for symptomatic cases refractory to medical therapy and for patients who have developed a tachycardia-mediated cardiomyopathy because of pro-longed exposure to rapid heart rates.1Table 1. Characteristics of Catheter Ablation for Selected Cardiac Arrhythmias ArrhythmiaAblation locationSuccess rate (%)Complication rate (%) Potential complications IndicationsAtrial tachycardiaVariable, anywhere in right or
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