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 permanent) 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 perforation with tamponade, thromboembolic events), or ablation energy delivery (e.g., atrioventricular nodal block).