title: Radiofrequency ablation of paroxysmal atrial fibrillation with the new irrigated multipolar nMARQ ablation catheter: verification of intracardiac signals with a second circular mapping catheter.
abstract: BACKGROUND
  During radiofrequency (RF) ablation of paroxysmal atrial fibrillation, a circular multielectrode recording "lasso" catheter is generally positioned within each pulmonary vein (PV) to determine when pulmonary vein potentials (PVPs) are present and when they have been ablated. The new irrigated multipolar nMARQ circular ablation catheter is positioned within the left atrium to create contiguous circular ablation lines around each PV ostium.
  
  
  OBJECTIVE
  To determine whether the recordings obtained from the nMARQ catheter position around the PV ostium accurately reproduce the recordings obtained from a lasso catheter positioned within that vein.
  
  
  METHODS
  In 10 patients undergoing RF ablation of paroxysmal atrial fibrillation, we placed an nMARQ and a lasso catheter around and within each PV, respectively. Recordings obtained from both catheters at baseline and after RF ablation were compared.
  
  
  RESULTS
  At baseline, recordings of PVPs in both catheters were concordant in 92% of all PVs. However, after RF delivery, the concordance between the nMARQ and lasso recordings was poor. The discordant result most commonly observed was disappearance of "PVPs" from the nMARQ catheter with persistence of PVPs in the lasso catheter (12 of 39 [30%]). Conversely, the delivery of RF frequently resulted in fragmented electrograms (pseudo-PVPs) on the nMARQ catheter despite evidence of PV isolation by lasso catheter recordings.
  
  
  CONCLUSIONS
  The use of an nMARQ catheter alone, as currently recommended, may lead to underestimation and overestimation of the number of RF applications required to achieve PV isolation.
authors.affiliation: Department of Cardiology, Tel Aviv Sourasky Medical Center and Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel. Electronic address: roswin1@gmail.com.
authors.forename: Raphael
authors.initials: R
authors.lastname: Rosso
authors.affiliation: Department of Cardiology, Tel Aviv Sourasky Medical Center and Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Amir
authors.initials: A
authors.lastname: Halkin
authors.affiliation: Department of Cardiology, Tel Aviv Sourasky Medical Center and Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Yoav
authors.initials: Y
authors.lastname: Michowitz
authors.affiliation: Department of Cardiology, Tel Aviv Sourasky Medical Center and Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Bernard
authors.initials: B
authors.lastname: Belhassen
authors.affiliation: Department of Cardiology, Tel Aviv Sourasky Medical Center and Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Aharon
authors.initials: A
authors.lastname: Glick
authors.affiliation: Department of Cardiology, Tel Aviv Sourasky Medical Center and Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Sami
authors.initials: S
authors.lastname: Viskin
mesh_terms: D001281:Atrial Fibrillation / Q000601:surgery*; D017115:Catheter Ablation / Q000295:instrumentation* / Q000379:methods; D057785:Catheters; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011667:Pulmonary Veins / Q000502:physiology
keywords: Atrial fibrillation; Pulmonary veins; Radiofrequency ablation