CATHETER ABLATION OF SINUS NODE TACHYCARD IA

Sinus node tachycardia is an uncommon cause of paroxysmal supraventric ular tachycardia. Of those patients who were referred to our clinic fo r electrophysiologic evaluation and catheter ablation, four patients ( 1 male, 3 female) were found to have sinus node tachycardia. The diagn osis of sinus node tachycardia required all of the following: The P-wa ve during sinus rhythm had to be similar to the P-wave during the tach ycardia, the atrial activation sequence during sinus rhythm and tachyc ardia had to be similar, the origin of the tachycardia had to be in th e high right atrium. In one patient the tachycardia was incessant. The other three patients had paroxysmal sinus node tachycardia that could be induced by programmed atrial stimulation. No patient had overt car diac disease. One patient had an inducible av nodal reentrant tachycar dia and one patient had a second atrial tachycardia originating from t he basal right atrium. Activation mapping during tachycardia was perfo rmed in all patients. Local atrial activation at the site of successfu l ablation preceded the P-wave in the surface electrocardiogram by 54 +/- 43 ms. In three patients the interval from the local atrial activa tion at the site of successful catheter ablation to the onset of the s ignal from the high right atrium (HRA) ranged from 25 ms to 125 ms, in one patient the signal from the high right atrium was the earliest re corded signal during tachycardia. In all patients the tachycardia was terminated with the application of radiofrequency current. Two to a ma ximum of 12 radiofrequency current applications were necessary; compli cations were not observed. In all patients a second electrophysiologic study was performed 8 +/- 2 weeks after successful catheter ablation; no patient had inducible sinus node or atrial tachycardia. During a f ollow-up of 5 +/- 2 months, no patient had a recurrence of sinus node tachycardia or required antiarrhythmic medication. It is concluded tha t catheter ablation in patients with sinus node tachycardia is an effe ctive and safe treatment.