Catheter ablation of atrioventricular nodal reentrant tachycardia

Electrophysiological data of atrioventricular nodal reentrant tachycardia recensed over the last 40 years in the animal and in man has not resolved the question as to the exact site of the reentry circuit: an exclusively intranodal pathway or a pathway involving part of the atrium? The remarkable efficacy of modern radical therapy of this arrhythmia with preservation of atrioventricular conduction reinforces the concept of reentry involving not only the atrioventricular node but also the juxta nodal atrium and the superior and inferior atrionodal connections. Radical treatment was initially surgical and then by catheter ablation. The technique of specific ablation of the rapid anterior pathway was the first to be described. Its limitation is the relatively high risk (about 10%) of complete atrioventricular block. Very quickly, radiofrequency ablation of the slow posterior pathway became the method of reference. Most patients do not have retrograde conduction in the slow pathway. The pathway is located in sinus rhythm by recording its specific potentials: either the rapid potential described by Jackman et al or the fragmented potential described by Haissaguerre and Warin. The former is recorded from the posterior septal position anterior to the orifice of the coronary sinus; the second is recorded at the same level but slightly above in the mid septal position. Ablation of the slow pathway can be performed on these purely anatomical criteria. Using these approaches, an immediate success rate of over 90% may be obtained. The recurrence rate is 0 to 5%; that of complete atrioventricular block ranges from 0 to 4%.(ABSTRACT TRUNCATED AT 250 WORDS)