EFFECTIVENESS OF RADIOFREQUENCY CATHETER ABLATION FOR TREATMENT OF ATRIAL TACHYCARDIA

Catheter ablation has been used to treat atrioventricular node reentra nt and atrioventricular reentrant tachycardias with extremely high suc cess rates. The suitability of catheter ablation for treatment of atri al tachycardia, a much less common type of supraventricular tachycardi a, has not been well addressed. Fifteen patients (8 females) ranging f rom 10 to 83 years (mean 38 +/- 22) were referred for catheter ablatio n of supraventricular tachycardia. The diagnosis of atrial tachycardia was established by standard electrophysiologic techniques. A combinat ion of activation and pace mapping was used to identify a suitable sit e for radiofrequency current catheter ablation. Medical therapy was un successful in all but 1 patient. Two patients had surgically corrected congenital heart disease, 2 had coronary artery disease and 1 had dil ated cardiomyopathy. Seven patients had depressed left ventricular fun ction. Six patients had incessant tachycardias. Presumed tachycardia m echanism was automatic in 11 patients and reentrant in 4. Mean tachyca rdia cycle length was 372 +/- 74 ms. Catheter ablation was acutely suc cessful in 12 patients (80%) with application of 11.1 +/- 6.6 lesions at a mean voltage of 60 +/- 9 V. In the other 3 patients, 16 to 38 les ions were applied. At a mean follow-up of 18.5 +/- 6.5 months, 2 patie nts have had recurrences with different P-wave morphologies and underw ent a second successful catheter ablation procedure. An additional 2 p atients had recurrences with the same P-wave morphology and 1 underwen t a second successful catheter ablation procedure. Thus, radiofrequenc y ablation can be used in a diverse population of patients with atrial tachycardia with an acute success rate of 80% and a long-term success rate of 73%.