Catheter ablation for patients with atrial tachycardia.

The advent of radiofrequency catheter ablation has revolutionized the treatment of patients with cardiac arrhythmias. In the 1980s, direct current was the only practical available energy source for ablation. 13,39 The unpredictable size of lesions created by direct current ablation, barotrauma, and difficulty in focally applying this energy source limited its applicability. From the late 1980s to the present, refinements in radiofrequency energy sources and catheter technology have resulted in explosive growth in the use of catheter ablation as a treatment for rhythm disturbances. Initially, radiofrequency energy was predominantly applied to create complete atrioventricular node interruption, to eliminate accessory pathways, or to treat ventricular tachycardia. 38 Trends illustrate a change in the demographics and pathologic substrates of the population undergoing radiofrequency ablation. Selective atrioventricular node modification is now performed as often as is ablation of accessory pathways. 37 It appears likely that atrioventricular node modification will supersede accessory pathway ablation in most laboratories in the future as it already has done in the author's laboratory. Coincident with the increase in the numbers of patients undergoing atrioventricular node modifications has been the application of this technique to other arrhythmic substrates, such as atrial tachycardia, atrial flutter, inappropriate sinus tachycardia, and most recently (at least in the experimental phase) atrial fibrillation. One primary advantage of radiofrequency ablation is its widespread applicability regardless of the underlying mechanism of the targeted arrhythmia. Automatic and reentrant arrhythmias are equally well eliminated. Nevertheless, an understanding of the clinical entity, underlying pathophysiology, and mechanisms helps the operator to ablate the arrhythmia successfully.