Direct left atrial ICE imaging guided ablation for atrial fibrillation without employing contrast medium

BackgroundPreoperative and intraoperative use of a contrast medium is unavoidable in catheter ablation for atrial fibrillation, which can become a particularly significant issue for patients suffering from renal impairment.ObjectiveThe purpose of this study is to investigate the feasibility and safety of a technique for atrial fibrillation ablation without a contrast medium via intra-cardiac ultrasound imaging only.MethodsWe prepared the geometry of the pulmonary vein and left atrium via a SOUNDSTAR catheter from inside the left atrium, without preoperative and intraoperative investigations using contrast mediums, for computed tomography or magnetic resonance imaging and pulmonary venography. This was followed by retrospective investigation of the success rate and complications observed in 200 successive paroxysmal and persistent atrial fibrillation cases that underwent catheter ablation from January 2011 to November 2012. The outcomes were assessed after the one-year follow-up.ResultsInserting a SOUNDSTAR catheter into the left atrium was successful in all cases, wherein rendering of all pulmonary veins and the left atrium was possible, and extensive encircling pulmonary vein isolation was successful in all cases. The sinus rhythm maintenance rate one year after the procedure was 90.4% for paroxysmal atrial fibrillation and 76.0% for persistent atrial fibrillation. The major complication rate was 0.5% (cardiac tamponade), with no cases presenting aggravation of renal function.ConclusionAtrial fibrillation ablation using an intra-cardiac ultrasound from the left atrium without employing a contrast medium was safe, with no adverse effects on renal function.