Mapping of Atrial Activation With a Noncontact, Multielectrode Catheter in Dogs

Abstract

Background-Endocardial mapping of sustained arrhythmias has traditionally been performed with a roving diagnostic catheter. Although this approach is adequate for many tachyarrhythmias, it has limitations. The purpose of this study was to evaluate a novel noncontact mapping system for assessing atrial tachyarrhythmias. Methods and Results-The mapping system consists of a 9F multielectrode-array balloon catheter that has 64 active electrodes and ring electrodes for emitting a locator signal. The locator signal was used to construct a 3-dimensional right atrial map; it was independently validated and was highly accurate. Virtual electrograms were calculated at 3360 endocardial sites in the right atrium. We evaluated right atrial activation by positioning the balloon catheter in the mid right atrium via a femoral venous approach. Experiments were performed on 12 normal mongrel dogs. The mean correlation coefficient between contact and virtual electrograms was 0.80Ϯ0.12 during sinus rhythm. Fifty episodes of atrial flutter induced in 11 animals were evaluated. In the majority of experiments, complete or almost complete reentrant circuits could be identified within the right atrium. Mean correlation coefficient between virtual and contact electrograms was 0.85Ϯ0.17 in atrial flutter. One hundred fifty-six episodes of pacing-induced atrial fibrillation were evaluated in 11 animals. Several distinct patterns of right atrial activation were seen, including single-activation wave fronts and multiple simultaneous-activation wave fronts. Mean correlation coefficient between virtual and contact electrograms during atrial fibrillation was 0.81Ϯ0.18. The accuracy of electrogram reconstruction was lower at sites Ͼ4.0 cm from the balloon center and at sites with a high spatial complexity of electrical activation. Conclusions-This novel noncontact mapping system can evaluate conduction patterns during sinus rhythm, demonstrate reentry during atrial flutter, and describe right atrial activation during atrial fibrillation. The accuracy of electrogram reconstruction was good at sites Ͻ4.0 cm from the balloon center, and thus the system has the ability to perform high-resolution multisite mapping of atrial tachyarrhythmias in vivo. (Circulation. 1999;99:1906-1913

Alterations in Electrophysiology and Tissue Structure of the Left Atrial Posterior Wall in a Canine Model of Atrial Fibrillation Caused by Chronic Atrial Dilatation

“…The standard EP catheter was used to create the geometry of the LA in the ESI software with a methodology that has been described elsewhere. 10,12 In brief, detailed geometries of the LA were obtained before mapping and the anatomic structures were marked on the reconstructed image. The noncontact mapping system sampled all 64 cavitary potentials on the MEA at 1,200 Hz and inversely applied them using the Laplace equation in real time.…”

“…Noncontact mapping technology can simultaneously record the endocardial activation of the entire chamber in which it is positioned, and has been demonstrated to be ideal for the study of atrial arrhythmias. [10][11][12] The aim of the present study was to use the noncontact mapping system to delineate the electrophysiological (EP) characteristics of the LAPW in a model of AF in dogs with CDLA.…”

Determination of Human Ventricular Repolarization by Noncontact Mapping

“…10,11,14 The system consists of a 64-multielectrode array (MEA) mounted on a 7.5-mL inflatable balloon on a 9F catheter, an amplifier system, and a Silicon Graphics Workstation. For left ventricular study, the MEA was introduced under fluoroscopic guidance from the left femoral artery via the retrograde transaortic route into the ventricle.…”

Analysis of QRS-T subtraction in unipolar atrial fibrillation electrograms

“…The noncontact array balloon with 64 electrodes was placed in the left atrium transeptally, and electrograms were collected using inverse solution mathematics and interpolation in an inside-out fashion allowing the reconstruction of up to 3,600 simultaneous unipolar AEGs projected to the atrium's anatomical 3D representation 3D geometry of the atrium performed at the beginning of the EP procedure. The array was not moved after geometry creation to avoid distortion of the isopotential maps [12][13][14][15][16][17] and the distance between the centre of the balloon and the patient's endocardium wall did not exceed 4 cm (checked with fluoroscopy).…”