Where to draw the mitral isthmus line in catheter ablation of atrial fibrillation: histological analysis.

AIMS A linear lesion between the left inferior pulmonary vein orifice and mitral annulus, the so-called mitral isthmus, may improve the success of catheter ablation for atrial fibrillation. Gaps in the lesion line, however, may facilitate left atrial flutter. The aim of the study was to determine the optimal location of the lesion line by serial sectioning of the isthmus area. METHODS AND RESULTS In a post-mortem study of 16 patients with normal left atria, serial sections of the isthmus area from 10 mm superior to and 30 mm inferior to the isthmus were studied by light microscopy. The length of the isthmus was 35+/-7 mm. On average, the muscle sleeve around the coronary sinus ended 10 mm inferior to the isthmus. The prevalence of a ramus circumflexus <5 mm from the endocardial surface, decreased from 60% in the most superior section to 0% in the most inferior section. Atrial arteries were frequently present in all sections. CONCLUSIONS The thickness of atrial myocardium, the ramus circumflexus sometimes very close to the endocardium, a myocardial sleeve around the coronary sinus, and local cooling by atrial arteries and veins may complicate the creation of conduction block in the mitral isthmus.

[1]  M. Hocini,et al.  The Left Atrial Isthmus: , 2004, Journal of cardiovascular electrophysiology.

[2]  I. Hisatome,et al.  Histopathologic Background for Resistance to Conventional Catheter Ablation of Common Atrial Flutter , 2004, Journal of cardiovascular electrophysiology.

[3]  A. Becker.  Left Atrial Isthmus: , 2004, Journal of cardiovascular electrophysiology.

[4]  Burr Hall,et al.  Catheter Ablation for Paroxysmal Atrial Fibrillation: Segmental Pulmonary Vein Ostial Ablation Versus Left Atrial Ablation , 2003, Circulation.

[5]  Sabine Ernst,et al.  Catheter-induced linear lesions in the left atrium in patients with atrial fibrillation: an electroanatomic study. , 2003, Journal of the American College of Cardiology.

[6]  M. Haissaguerre,et al.  Linear Ablation in the Left Atrium Using a Nonfluoroscopic Mapping System , 2003, Journal of cardiovascular electrophysiology.

[7]  M. Wood,et al.  Intramural Coronary Vasculature Prevents Transmural Radiofrequency Lesion Formation: Implications for Linear Ablation , 2003, Circulation.

[8]  Javier Moreno,et al.  Left Atrial Flutter After Radiofrequency Catheter Ablation of Focal Atrial Fibrillation , 2003, Journal of cardiovascular electrophysiology.

[9]  L. Leite,et al.  Mechanical reperfusion of acute right coronary artery occlusion after radiofrequency catheter ablation and long-term follow-up angiography. , 2003, The Journal of invasive cardiology.

[10]  D. Shah,et al.  Irrigated‐Tip Catheter Ablation of Pulmonary Veins for Treatment of Atrial Fibrillation , 2002, Journal of cardiovascular electrophysiology.

[11]  F. Anselme,et al.  Acute Coronary Occlusion During Radiofrequency Catheter Ablation of Typical Atrial Flutter , 2002, Journal of cardiovascular electrophysiology.

[12]  Ottavio Alfieri,et al.  Atrial Electroanatomic Remodeling After Circumferential Radiofrequency Pulmonary Vein Ablation Efficacy of an Anatomic Approach in a Large Cohort of Patients With Atrial Fibrillation , 2002 .

[13]  Michel Haïssaguerre,et al.  Ablation therapy for atrial fibrillation (AF): past, present and future. , 2002, Cardiovascular research.

[14]  S. Ernst,et al.  Characterization of Reentrant Circuits in Left Atrial Macroreentrant Tachycardia: Critical Isthmus Block Can Prevent Atrial Tachycardia Recurrence , 2002, Circulation.

[15]  Hakan Oral,et al.  Pulmonary Vein Isolation for Paroxysmal and Persistent Atrial Fibrillation , 2002, Circulation.

[16]  E. Rowland,et al.  Tissue rupture and bubble formation during radiofrequency catheter ablation: "echoes of a pop". , 2001, Circulation.

[17]  Gabriele Vicedomini,et al.  Circumferential Radiofrequency Ablation of Pulmonary Vein Ostia A New Anatomic Approach for Curing Atrial Fibrillation , 2000 .

[18]  J Clémenty,et al.  Mapping and ablation of left atrial flutters. , 2000, Circulation.

[19]  J Clémenty,et al.  Electrophysiological end point for catheter ablation of atrial fibrillation initiated from multiple pulmonary venous foci. , 2000, Circulation.

[20]  D. Shah,et al.  Efficacy and safety of septal and left-atrial linear ablation for atrial fibrillation. , 1999, The American journal of cardiology.

[21]  Robert H. Anderson,et al.  Anatomy of the Left Atrium: , 1999, Journal of cardiovascular electrophysiology.

[22]  F. Cosío,et al.  Living anatomy of the atrioventricular junctions. A guide to electrophysiologic mapping. A Consensus Statement from the Cardiac Nomenclature Study Group, Working Group of Arrhythmias, European Society of Cardiology, and the Task Force on Cardiac Nomenclature from NASPE. , 1999, Circulation.

[23]  J Clémenty,et al.  Spontaneous initiation of atrial fibrillation by ectopic beats originating in the pulmonary veins. , 1998, The New England journal of medicine.

[24]  F. Leclercq,et al.  Chronic Left Main Coronary Artery Occlusion: A Complication of Radiofrequency Ablation of Idiopathic Left Ventricular Tachycardia , 1997, Pacing and clinical electrophysiology : PACE.

[25]  R Lazzara,et al.  Comparison of in vivo tissue temperature profile and lesion geometry for radiofrequency ablation with a saline-irrigated electrode versus temperature control in a canine thigh muscle preparation. , 1995, Circulation.

[26]  A R Jayaweera,et al.  Effects of radiofrequency catheter ablation on regional myocardial blood flow. Possible mechanism for late electrophysiological outcome. , 1994, Circulation.

[27]  Michael v. Lüdinghausen,et al.  Myocardial coverage of the coronary sinus and related veins , 1992 .