[Selective catheter ablation of the slow pathway in a patient with recurrent atrioventricular nodal reentrant tachycardia].

The case of a 35 year-old patient with recurrent, sustained atrioventricular nodal reentry tachycardia (AVNRT)--type slow/fast--refractory to group IA, IC, II, IV antiarrhythmic agents is presented. The maximum rate of the tachycardia was 280/min. During the antiarrhythmic treatment with group IA, IC and IV agents the tachycardia rate was 230/min. The effective refractory period (ERP) of the slow pathway was 200 ms in antegrade direction. ERP of the fast pathway was 260 ms in antegrade and 210 ms in retrograde direction. Ablation of the slow pathway was performed with radiofrequency energy (device HAT 200 S manufactured by Osypka GMBH, catheter Cereblate No 6). The total ablation time was 96 s, maximal temperature of the effective ablation time was 51 centrigrades. Total energy delivered was 2316 J. The ablation caused neither atrioventricular conduction block nor any damage to the heart structure other than the slow conduction pathway. After the ablation there are no evidence of conduction through the slow pathway. Conduction in anterograde and retrograde direction occurs through the fast pathway. No AVNRT were observed. After ablation the patient has no antiarrhythmic treatment.