LONG-TERM FOLLOW-UP IN PATIENTS WITH THE PERMANENT FORM OF JUNCTIONALRECIPROCATING TACHYCARDIA TREATED WITH RADIOFREQUENCY ABLATION

Objectives. This study sought to determine the long-term follow-up, sa fety and efficacy of radiofrequency catheter ablation in patients with the permanent form of junctional reciprocating tachycardia. We assess ed the reversibility of tachycardia-related left ventricular dysfuncti on and we detailed the location and electrophysiologic characteristics of these atrioventricular decremental pathways. Background. Permanent junctional reciprocating tachycardia is an infrequent form of recipro cating tachycardia, commonly incessant and usually drug-refractory. Th e electrocardiographic hallmarks include an RP interval > PR with inve rted P waves in leads II, III, aVF and V3-V6. During tachycardia, retr ograde ventriculo-atrial conduction occurs over an accessory pathway w ith decremental conduction properties, located predominantly in the po steroseptal zone. It is known that long lasting and incessant tachycar dia may result in tachycardia-related severe ventricular dysfunction, the so called tachycardiomyopathy. Patients and methods. We included 2 4 patients (9 males, 15 females; mean age 42 +/- 22 years) with the di agnosis of permanent junctional reciprocating tachycardia at electroph ysiologic study. Six patients had tachycardia-related left ventricular dysfunction. Radiofrequency energy was delivered at the site of earli est retrograde atrial activation during reciprocating tachycardia (n = 22) or ventricular pacing (n = 2). All patients were followed at the outpatient clinic and serial echocardiograms were performed in those w ho presented depressed left ventricular function. Results. Radiofreque ncy catheter ablation was performed in 24 decremental accessory pathwa ys. Earliest retrograde atrial activation was right posteroseptal in 2 2 patients (92%), right midseptal in 1 (4%) and right posterolateral i n 1 (4%). Twenty-three accessory pathways were successfully ablated wi th a mean of 5 +/- 3 (median, 4) radiofrequency applications of a mean duration of 48 +/- 13 s. Only the midseptal accessory pathway could n ot be ablated. After a mean follow-up of 21 +/- 16 months (median, 15; range 2 to 64) 22 patients remain asymptomatic. There were recurrence s in 4 patients after the initial successful ablation (three during th e first month and one during the second month after the procedure), tw o were ablated in a second ablation procedure, one patient required a third procedure and one required a fourth. All patients with left vent ricular dysfunction experienced an improvement after ablation. Mean pr eablation left ventricular ejection fraction in patients with tachycar diomyopathy was 28 +/- 6% (median, 27) and raised to 51 +/- 16% (media n, 47) after ablation (p < 0.02). Conclusions. Our study supports the concept that radiofrequency catheter ablation is a safe and useful tre atment for patients with permanent junctional reciprocating tachycardi a, Radiofrequency current should be the treatment of choice in these p atients because this arrhythmia is usually drug-refractory. The majori ty of accessory pathways with decremental conduction properties are lo calized in the posteroseptal zone. Cessation of the arrhythmia after s uccessful ablation results in recovery of left ventricular dysfunction .