Surgical and catheter ablative techniques for treating supraventricular tachycardia

Although antiarrhythmic drugs are commonly used in patients with supraventricular tachycardia, their use is limited due to inefficacy, side effects and patient compliance problems. Nonpharmacologic therapies used in the treatment of supraventricular tachycardia include: antitachycardia pacing, DC and radiofrequency catheter ablation and surgical therapy. Although certain pacing techniques can prevent the initiation of tachycardia, antitachycardia pacing is primarily used to terminate the supraventricular tachycardia once it has occurred. In patients with primary atrial tachycardias that are refractory to treatment, DC or radiofrequency catheter ablation can be used to modify or completely ablate the AV junction with resultant complete heart block. With DC AV junction ablation, 65% of patients will have resultant third degree AV block and 20% of patients will have modification of AV condition. Results with radiofrequency ablation have shown efficacy rates ranging from 56-9470 and can be used without the need for general anesthesia. Both forms of catheter ablation can be used to selectively alter the retrograde limb of an AV node reentrant circuit. Catheter ablation has been successful in ablating accessory pathways. DC catheter ablation has been predominantly used in posterior paraseptal pathways. More recently, radiofrequency catheter ablation of the ventricular insertion site of accessory pathways has demonstrated usefulness in selective laboratories. Surgical therapy for supraventricular tachycardia has been used for excision and/or ablation of an atrial ectopic focus, surgical ablation of the AV node in patients with refractory atrial tachyarrhythmias and microsurgery of the AV node in patients with AV node reentrant tachycardia.(ABSTRACT TRUNCATED AT 250 WORDS)