Techniques of mapping and isolation of the pulmonary veins in patients with atrial fibrillation

Abstract

Electrical isolation of the pulmonary veins (PVs) is now the cornerstone of the ablative treatment of atrial fibrillation (AF). Traditional catheter ablation that applies the “point-by-point” approach guided by a three- dimensional imaging system is technically complex and time-consuming. Thus, there is a continuing search for alternative methods for ablation and imaging that should be as effective but more easily with shorter procedure times and a reduced complexity of the procedure. Cryoballoon with a micromapping catheter inserted through the central lumen, pulmonary vein ablation catheter (PVAC®), the high-density mesh ablation catheter (MESH) are widespread used but never underwent a direct comparison regarding efficacy; three-dimensional rotational angiography or atriography (3D-ATG) is the new electrophysiologic (EP) imaging technique which combines the accuracy of direct angiography with the benefits of computer animation. Objective The purpose of this study was to: (1) assess the efficacy and safety of the new ablation catheters such as novel cryoballoon catheter, PVAC, and the MESH catheter compared with the conventional point-by-point RF ablation catheter; (2) compare the procedural and clinical outcome of catheter ablation for AF using either three- dimensional electroanatomical mapping (CARTO) or 3D-ATG. Methods (1) From January 2008 to July 2010, 176 consecutive patients with symptomatic AF (mean age 61±11 years, 67.0% paroxysmal AF, 33.0% persistent AF) were divided to ablation using simplified cryoballoon catheter (52 patients), PVAC (46 patients), the MESH catheter (26 patients), and open-irrigation RF ablation catheter (52 patients). (2) From January 2007 to December 2008, 134 consecutive patients with symptomatic AF (mean age 59±11 years, 56.7% paroxysmal AF, 43.3% persistent AF) were randomized to ablation using either 3D-ATG (66 patients) or CARTO (68 patients). Results (1) There were no significant differences of complete PV isolation (71.2% of cryoballoon, 76.1% of PVAC, 65.4% of MESH, and 76.9% of RF, respectively, P>0.05) and successful isolation of targeted PVs (88.5% of Cryoballoon, 95.1% of PVAC, 90.4% of MESH, and 91.8% of RF, respectively, P>0.05) among the four groups. Procedure time was lowest in the PVAC group (P<0.001); fluoroscopy time was lowest in the MESH group (P<0.001). One patient had phrenic nerve palsy in the cryoballoon group, one case of air embolism was observed in the PVAC group, and one Tamponade was observed in the MESH group. There were no significant differences of complication rate among the four groups. After a mean follow-up of 11±8 months, there was no significant difference in clinical outcome among the four groups concerning AF recurrence (P=0.25). (2) Procedure time, fluoroscopy time, RF ablation time, radiation exposure was shorter in the 3D- ATG group: 185.1±35.0 minutes versus. 233.1±50.8 minutes, P<0.001; 44.0±13.0 minutes vs. 57.1±29.2 minutes, P<0.001; 34.3±15.2 minutes vs. 47.0±17.9 minutes; P<0.001; 155417.2±80487.9 mGy cm2 vs. 223409.0±144649.1 mGy cm2, P=0.001; respectively. There were no major complications. After a mean follow- up of 14±13 months, there was no significant difference in clinical outcome using either 3D-ATG or CARTO concerning the AF recurrence (59.1% vs. 58.8%, P=0.784). Conclusions (1) Simplified cryoballoon, PVAC, and the MESH catheter all represent safe, efficacious alternative for PV isolation. They all reduce both procedure and fluoroscopy time and make the procedure simple. The short- and middle-term efficacy of these catheters is comparable to a conventional point-by-point ablation technique. (2) Three-dimensional ATG allows AF ablation to be guided with lower radiation exposure, shorter procedure time and similar outcome compared with CARTO. The ease of use and accurate 3D representation of the LA anatomy make 3D-ATG a reasonable alternative to conventional 3D electroanatomic mapping systems, however, without advanced mapping functions.

Vereinfachte Kryoballon, PVAC und die MESH Katheter alle repräsentieren sichere, wirksame Alternative für PV-Isolation. Sie alle reduzieren sowohl Verfahren und Durchleuchtung Zeit und machen das Verfahren einfach. Die kurz- und mittelfristige Wirksamkeit dieser Katheter ist vergleichbar mit einem herkömmlichen Punkt-zu-Punkt-Ablation Technik. 3D-ATG ermöglicht AF-Ablation mit geringerer Strahlenbelastung, kürzere Verfahren Zeit und ähnliches Ergebnis verglichen mit CARTO geführt werden. Die einfache Handhabung und präzise 3D-Darstellung der Anatomie LA machen 3D-ATG eine vernünftige Alternative zu herkömmlichen 3D-Mapping-Systeme elektroanatomischen jedoch ohne erweiterte Mapping-Funktionen.