Diagnosis and Ablation of Atrial Flutter Using a High Resolution, Noncontact Mapping System

Abstract

SCHMITT, H., ET AL.: Diagnosis and Ablation of Atriai Flutter Using a High Resolution, Noncontact Mapping System. The ablation of atriai flutter can sometimes be time consuming and unsuccessful using conventional catheter techniques especially in patients with recurrences after previous ablation procedures. Simultaneous high resolution mapping from multiple sites may overcome some of the limitations. Therefore, a new high resolution noncontact mapping system was used for diagnosis and ablation of atria! flutter in 15 patients. The mapping systein consists of a catheter-mounted multielectrode array, an amplifier, and a computer workstation. Far-field potentials recorded by the multielectrode catheter are amplified, digitized, and sampled at 1.2 kHz, and digitally filtered to construct high resolution activation maps during tachycardia. Ablation catheters can be steered to target sites without fluoroscopy. In 12 of the 15 patients the analysis of the activation sequence during tachycardia showed a counter-clockwise, and in 1 of 15 patients a clockwise, rotating wavefront using the isthmus as pad of the reentrant circuit. In two patients no tachycardia could be induced. In 3 of the 15 patients with previous conventional ablation procedures the gap in the line of block in the isthmus region was identified and marked on the animation model. The isthmus in the right atrium was ablated and isthmus block verified by the mapping system in all patients. No complications were observed. No recurrences of atria! flutter occurred during fol!ow-up of 4 ± 1.7 months. The total procedure and fluoroscopy time was 171 ± 50.0 minutes and 24 ± 12.7 minutes, respectively. In conclusion, the use of the new high resolution noncontact mapping system in patients with right atrial flutter is safe and higl^ly effective. In patients with previously failed conventional ablation procedures the use of a noncontoct mopping system may facilitate the identification of the gap in the line of block in the isthmus region and reablation of atria! f!utter. (PACE 2000; 23:2057-2064 atriai flutter, mapping, ablation

Characteristics of virtual unipolar electrograms for detecting isthmus block during radiofrequency ablation of typical atrial flutter

“…Moreover, change of contact unipolar electrograms in the RA opposite the pacing site seems to be useful for detecting complete CTI block after radiofrequency ablation (RFA) of the CTI (12). The noncontact mapping system has been demonstrated to facilitate RFA of typical AFL because it shows simultaneous three-dimensional activation in the whole RA (13,14). Furthermore, this system also can show local virtual unipolar electrograms along the ablation line.…”

Biatrial Activation in Isthmus-Dependent Atrial Flutter

“…A detailed mapping of isthmus-dependent or typical atrial flutter (AFL) using multiple endocardial recordings, 1,2 intracardiac echocardiography, 3 electroanatomic CARTO, 4 64-electrode basket catheter, 5 noncontact EnSite, 6 and body surface mapping 7 has shown a right atrial (RA) macroreentrant circuit around the tricuspid annulus. Although mapping of the right side of the atrial septum was performed in several of these studies, the site of interatrial connections and the pattern of left atrial (LA) activation have been described only in animal models.…”