Endocardial catheter fulguration for treatment of atrial flutter

Abstract

Endocardial catheter fulguration is a technique that was recently proposed for the treatment of certain cardiac arrhythmias. The aim is to destroy or to modify electrophysiologic properties of arrhythmogenic areas, or to interrupt the His bundle or accessory pathways in case of supraventricular tachycardias. There have been few successful attempts to fulgurate right atrial automatic focus, in both infants and adults. 1,2 The treatment of flutter has not been assessed; we report here the 2 first cases. For each patient, we had to delimit very precisely the area of slow conduction, which is responsible for the reentry circuit within the atrium. The area of human common flutter is very often located in the right atrium, near the opening of the coronary sinus. 3 This has been confirmed by mapping during thoracotomy, thereby allowing the treatment of 2 patients with flutter by cryosurgical ablation. 4 It is difficult, however, to determine by catheter where depolarization begins within the atrium, because of the incessant movement of the wave front. Nevertheless, mappings have demonstrated that there is a short time during the flutter cycle (40 to 70 ms) when it is not possible to obtain any electrogram or only fragmented electrograms can be observed. 3,5 Fragmented electrograms recorded by bipolar electrodes have been studied by Cosio et al, 5 who found them in 13 patients. They were able to demonstrate that the fragmented electrograms were included in the right atrium loop of flutter, and were probably related to a slow conduction area responsible for the reentrant circuit. Olshanski et al 3 also found a double potential located in the lower part of the right atrium in 10 patients with chronic flutter. They studied this phenomenon by transient atrial entrainment and concluded that the area where this double potential can be observed during flutter is a localized reentry with block and can be considered a marker of the center of the flutter.