Regional left atrial interstitial remodeling in patients with chronic atrial fibrillation undergoing mitral-valve surgery

• Published in: Virchows Archiv : an international journal of pathology Vol. 445; no. 5; pp. 498 - 505
• Main Authors: CORRADI, Domenico, CALLEGARI, Sergio, BENUSSI, Stefano, NASCIMBENE, Simona, PASTORI, Paolo, CALVI, Simone, MAESTRI, Roberta, ASTORRI, Ettore, PAPPONE, Carlo, ALFIERI, Ottavio
• Format: Journal Article
• Language: English
• Published: Berlin Springer 01.11.2004; Springer Nature B.V
• Subjects: Adult; Aged; Aged, 80 and over; Atrial Appendage - physiopathology; Atrial Fibrillation - physiopathology; Atrial Fibrillation - surgery; Biological and medical sciences; Cardiac arrhythmia; Cardiac dysrhythmias; Cardiology. Vascular system; Chronic Disease; Female; Heart; Heart Valve Diseases - physiopathology; Heart Valve Diseases - surgery; Humans; Investigative techniques, diagnostic techniques (general aspects); Male; Medical sciences; Middle Aged; Mitral Valve - surgery; Myocardium - ultrastructure; Pathology. Cytology. Biochemistry. Spectrometry. Miscellaneous investigative techniques; Human; Mitral valve; Arrhythmia; Atrial fibrillation; Cardiovascular disease; Left atrium; Regional; Remodeling; Ablation; Excitability disorder; Anatomic pathology; Chronic; Treatment; Heart disease; Surgery; Fibrosis; Interstitial; Capillaries
• ISSN: 0945-6317; 1432-2307
• DOI: 10.1007/s00428-004-1040-2

Ablation of the left atrial free wall around the pulmonary vein ostia (LAFW) may be effective in the treatment of chronic atrial fibrillation associated with mitral disease (CAF-MVD). Using light and conventional electron microscopy analyses, we wanted to evaluate, in CAF-MVD, the interstitial remodeling in the LAFW as well as in a more remote region, such as the left atrial appendage (LAA). LAFW and LAA samples were obtained from 33 CAF-MVD patients during combined mitral surgery and radiofrequency ablation and from 16 autoptic controls. Interstitial fibrosis (IF) and perivascular fibrosis (PF), capillary densities and the maximal oxygen diffusion distance were morphometrically determined. In CAF-MVD patients, the LAFW, compared with the LAA, showed a higher percentage of IF (7.16+/-3.23% versus 2.51+/-1.40%, respectively), a lower myocardial capillary density per mm(2) (830+/-106 versus 989+/-173) and an increased oxygen maximal diffusion distance (19.70+/-1.27 microm versus 18.13+/-1.58 microm). All these values were also significantly different than controls. No differences were found in evaluating PF. At variance with the LAA, in CAF-MVD patients, the LAFW around the pulmonary vein ostia is a region characterized by a marked interstitial remodeling such that it may be morphologically indicated as an appropriate target for ablation treatment aimed at sinus rhythm restoration.