INITIAL AND LONG-TERM EVALUATION OF ESCAPE RHYTHM AFTER RADIOFREQUENCY ABLATION OF THE AV JUNCTION IN 50 PATIENTS

Between 1986 and 1994, 50 patients (mean age 63 +/- 13 years), 25 of w hom had organic heart disease and presenting with atrial arrhythmias r efractory to 5.6 +/- 1.6 antiarrhythmic drugs, underwent radiofrequenc y ablation (5 +/- 3 pulses by procedure; duration of pulses 50.5 +/- 3 2 s) of the proximal AV junction to create complete and permanent AV b lock. The escape rhythm was studied immediately after the procedure an d during long-term follow-up. immediately after the procedure, an esca pe rhythm was observed in 80% of the patients (junctional in 92%). Ove r a mean follow-up of 36 +/- 16 months in 47 patients (2 patients died before assessment of escape rhythm and 1 was lost to follow-up), an e scape rhythm was present in 39 patients (83%) and absent in the remain ing 8 (17%). The only significant difference between the two groups wa s the initial presence of an escape rhythm (P = 0.008). However, three patients with an initial escape rhythm had none during long-term foll ow-up. The initial presence of an escape rhythm as a predictive factor of its presence during follow-up had a sensitivity of 87%, specificit y of 63%, positive predictive value of 92%, and negative predictive va lue of 50%. Thus, the absence of an escape rhythm during long-term fol low-up causing pacemaker dependency was noted in 1 of 6 patients. This represents a limitation to this palliative treatment, which should be reserved for patients suffering from supraventricular tachycardias re fractory to other treatments.