[Escape rhythms after ablation of the atrioventricular junction and implantation of a pacemaker].

Escape rhythms characteristics after successful catheter ablation of the atrioventricular junction and intentional complete heart block were compared with those due to others etiologies as well as the advantage of the posterior implantation of a rate responsive pacemaker (VVIR). In 22 patients, 9 men and 13 women, with permanent AV block after fulguration and follow-up periods from 4 to 58 months, escape rhythms data studied during the procedure and at short and long-term periods, showed the following characteristics: 1) Classical parameters of valuation are not as a whole useful to evaluate subsidiary escape rhythms after electrical fulguration of the atrioventricular junction system. 2) The QRS morphology of the escape rhythm exhibited frequently right or left bundle branch block and specially the former. 3) Spontaneous variability of the escape rhythm recovery time makes this parameter unreliable. 4) Electrophysiological parameters previous to the shock and energy delivery do not predict the origin and characteristics of the subsidiary escape rhythms. 5) Active ventricular arrhythmias appearing immediately postshock are unrelated with any subsequent complication. 6) Permanent pacing increases pacemaker dependency at least temporarily. In 15 of 22 patients, a rate responsive multiprogrammable pacemaker controlled by QT interval was implanted. Cardiac performance and life-quality was improved in these patients due to the addition of several factors: 1) Control of the tachyarrhythmias. 2) Elimination of antiarrhythmic drugs and their side-effects on ventricular function. 3) Self-regulation of cardiac rate through permanent stimulation with a QT sensitive rate responsive pacemaker.