RIGHT AND LEFT ATRIAL RADIOFREQUENCY CATHETER THERAPY OF PAROXYSMAL ATRIAL-FIBRILLATION

Introduction: Atrial fibrillation (AF), the most common arrhythmia, is due to multiple simultaneous wavelets of reentry in the atria. The on ly available curative treatment is surgical, using atriotomies to comp artmentalize the atria. Therefore, we investigated a staged anatomical approach using radiofrequency catheter ablation lines to prevent paro xysmal AF, Methods and Results: Forty-five patients with frequent symp tomatic drug-refractory episodes of paroxysmal AF were studied, Progre ssively complex linear lesions were created by sequential applications of radiofrequency current in the right atrium and then in the left at rium if required. The outcome of the procedure was considered a succes s when the episodes of AF were either eliminated or recurred at a rate of no more than one episode (lasting < 6 hours) in 3 months, Patients who had no more than one episode per month were considered ''improved .'' Right atrial ablation organized local electrical activity and led to stable sinus rhythm during the procedure in 18 (40%) of the 45 pati ents. However, sustained AF remained inducible in 40 of 45 patients, a nd the lesions failed to produce evidence of a significant linear cond uction block/delay in all but four patients. There were no significant complications except for two transient sinus node dysfunctions. The p rocedure duration and fluoroscopic time were 248 +/- 79 and 53 +/- 22 min, respectively. Additional sessions were required in 19 patients to treat sustained right atrial flutter or arrhythmias linked to ectopic right or left atrial foci. During a mean follow-up of 11 +/- 4 months , right atrial ablation was successful in 15 (33%) patients, 6 without medication and 9 with a previously ineffective drug, Nine (20%) addit ional patients were improved. Ten patients with an unsuccessful outcom e then underwent linear ablation in the left atrium. The procedure dur ation and fluoroscopy time were 292 +/- 94 and 66 +/- 24 min. A hemope ricardium occurred in one patient. Two patients required reablation to treat ectopic atrial foci, Left atrial ablation terminated AF during the procedure in 8 patients, and sustained AF could not be induced in 5. Subsequent success was achieved in 6 (60%) patients, including 4 wi thout medication, and 1 additional patient was improved, Conclusions: Successful radiofrequency catheter ablation of drug-refractory daily p aroxysmal AF is feasible using linear atrial lesions complemented by f ocal ablation targeted at arrhythmogenic foci. Ablation only in the ri ght atrium is a safe technique providing limited success, whereas line ar lesions in the left atrium significantly increase the incidence of stable restoration of sinus rhythm, the inability to induce sustained AF, and the final success rate. The described technique is promising b ut must be considered preliminary because significant improvements are required to optimize lesion characteristics and shorten total procedu re duration.