Background-Patients with nonischemic left ventricular cardiomyopathy (LVCM) and ventricular tachycardia (VT) havecomplex 3-dimensional substrate with variable involvement of the endocardium (ENDO) and epicardium (EPI). The purpose of this study was to determine whether ENDO unipolar (UNI) mapping with a larger electric field of view could identify EPI low bipolar (BIP) voltage regions in patients with LVCM undergoing VT ablation. Methods and Results-The reference value for normal ENDO unipolar voltage was determined from 6 patients without structural heart disease. Consecutive patients undergoing VT ablation over an 8-year period with detailed (Ͼ100 points) LV ENDO and EPI mapping and normal LV ENDO BIP voltage were identified. From this cohort, we compared patients with structurally normal hearts and normal EPI BIP voltage (EPIϪ, group 1) with patients with LVCM and low LV EPI BIP voltage regions present (EPIϩ, group 2). Confluent regions of ENDO UNI and EPI BIP low voltage (Ͼ2 cm 2 ) were measured. The normal signal amplitude was Ͼ8.27 mV for LV ENDO UNI electrograms. Detailed LV ENDO-EPI maps in 5 EPIϪ patients were compared with 11 EPIϩ patients. Confluent ENDO UNI low-voltage regions were seen in 9 of 11 (82%) of the EPIϩ (group 2) patients compared with none of 5 EPIϪ (group 1) patients (PϽ0.001). In all 9 patients with ENDO UNI low voltage, the ENDO UNI low-voltage regions were directly opposite to an area of EPI BIP low voltage (61% ENDO UNI-EPI BIP low-voltage area overlap). Conclusions-EPI arrhythmia substrate can be reliably identified in most patients with LVCM using ENDO UNI voltage mapping in the absence of ENDO BIP abnormalities. (Circ Arrhythm Electrophysiol. 2011;4:49-55.)

Background-During left atrial (LA) catheter ablation, an atrioesophageal fistula can develop as a result of thermal injury of the esophagus during ablation along the posterior LA. No in vivo studies have examined the relationship of the esophagus to the LA. The purpose of this study was to describe the topographic anatomy of the esophagus and the posterior LA by use of CT. Methods and Results-A helical CT scan of the chest with 3D reconstruction was performed in 50 patients (mean age, 54Ϯ11 years) with atrial fibrillation before an ablation procedure. Consecutive axial and sagittal sections of the CT scan were examined to determine the relationship, size, and thickness of the tissue layers between the LA and the esophagus. The mean length and width of the esophagus in contact with the posterior LA were 58Ϯ14 and 13Ϯ6 mm, respectively. The esophagus had a variable course along the posterior LA. The esophagus was close (10Ϯ6 mm from the ostia) and parallel to the left-sided pulmonary veins (PVs) in 56% of patients and had an oblique course from the left superior PV to the right inferior PV in 36% of patients. The mean thicknesses of the posterior LA and anterior esophageal walls were 2.2Ϯ0.9 and 3.6Ϯ1.7 mm, respectively. In 98% of patients, there was a fat layer between the esophagus and the posterior LA. However, this layer was often discontinuous. Conclusions-The

The purpose of this work is to prove existence and uniqueness results of suitably smooth solutions for an isothermal model of capillary compressible fluids derived by J.E. Dunn and J. Serrin (1985), which can be used as a phase transition model. We first study the well-posedness of the model in spaces with critical regularity indices with respect to the scaling of the associated equations. In a functional setting as close as possible to the physical energy spaces, we prove global existence of solutions close to a stable equilibrium, and local in time existence for solutions when the pressure law may present spinodal regions. Uniqueness is also obtained. Assuming a lower and upper control of the density, we also show the existence of weak solutions in dimension 2 near equilibrium. Finally, referring to the work of Z. Xin (1998) in the non-capillary case, we describe some blow-up properties of smooth solutions with finite total mass. © 2001 Éditions scientifiques et médicales Elsevier SAS RÉSUMÉ.-On s'intéresse ici à des résultats d'existence et d'unicité de solutions pour un modèle de fluides compressibles isothermes avec capillarité. Ce modèle de transition de phase a été dérivé par J.E. Dunn et J. Serrin (1985). Pour commencer, on montre que le problème de Cauchy est bien posé dans des espaces à régularité critique pour le scaling des équations. Pour des données initiales proches d'un état d'équilibre stable, on obtient l'existence globale (et l'unicité) de solutions dans un cadre fonctionnel aussi proche que possible de l'espace d'énergie physique. Pour des lois de pression plus générales (pouvant être décroissantes), on prouve des résultats locaux en temps. En supposant que l'on dispose d'un minorant strictement positif et d'une borne supérieure pour la densité, on obtient l'existence de solutions faibles en dimension 2 pour des données initiales proches de l'équilibre. Enfin, en adaptant un travail de Z. Xin pour les fluides sans capillarité, on établit l'explosion de solutions régulières à masse totale finie.

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Background-Delayed enhanced magnetic resonance imaging (DE-MRI) can be used for the exact assessment of myocardial infarct scar. Electroanatomic (EA) mapping can identify the subendocardial extension of infarcts and is used to identify and eliminate areas critical for postinfarction ventricular arrhythmias. The purpose of this study was to correlate DE-MRI with EA mapping in post-infarction patients with ventricular arrhythmias to assess myocardial infarct architecture and its relationship to post-infarction ventricular arrhythmias.

Abstract.Motivated by rotating fluids, we study incompressible fluids with anisotropic viscosity.We use anisotropic spaces that enable us to prove existence theorems for less regular initial data than usual. In the case of rotating fluids, in the whole space, we prove Strichartz-type anisotropic, dispersive estimates which allow us to prove global wellposedness for fast enough rotation.Mathematics Subject Classification. 35Q30, 35Q35, 76U05.

In patients undergoing AF ablation, EAM derived LA bipolar voltage shows regional variation. For maps acquired during SR, a voltage range of 0.2-0.45 mV can accurately demarcate LA scar distribution. This can be helpful in identifying PV reconnection in patients undergoing repeat AF ablation.