TYPES OF FIBROSIS AND ITS PREVALENCE IN ATRIA DURING ATRIAL FIBRILLATION IN PATIENTS WITH CORONARY ARTERY DISEASE AND RHEUMATIC HEART DISEASE

To assess the area and type of myocardial fibrosis in atrial fibrillation (AF), studied were 40 hearts, hospital case reports, and autopsy reports of patients with coronary artery disease (CAD) and rheumatic mitral valve disease (RMVD) aged 38 86 years (22 men and 18 women). Five groups of patients were identified. Group I consisted of 10 patients aged 68±10 years with CAD, but without AF. Group II consisted of 10 patients aged 68±10 years with CAD and paroxysmal AF. Group III included 10 patients aged 68±10 years with CAD and permanent AF. The patients with RMVD and paroxysmal AF (5 patients aged 53±9 years) constituted Group IV and those with RMVD and permanent AF (5 patients aged 59±7 years), Group V. For the histological study, the following structures were collected: 1) the right atrium wall in the area of crista terminalis, 2) Bachmann bundle, 3) the left atrium wall between the ostia of upper pulmonary veins, 4) the left atrium wall between the ostia of lower pulmonary veins, and 5) the left atrium wall in the middle between the ostia of upper and lower pulmonary veins. Hematoxylin eosin stain, Van Gieson’s stain, and Masson’s trichrome stain with additional hematoxylin stain (Bio-optica, Italy) of paraffin cuts were performed. In each atrial cut, the fibrosis type and its extent (0 through 4 points) were assessed. In the patients with CAD without AF, a mild perivascular fibrosis was revealed (1-2 points) evenly distributed in all studied areas, the relative fibrosis area was 5 8%. In patients with CAD and paroxysmal and permanent AF, the microfocal, perivascular, perimuscular fibrosis, and “armour fibrosis” were found. In case of permanent AF, the relative fibrosis area in all studied zones was statistically significantly more pronounced than in the coronary patients without AF. The consolidated group of patients with CAD and AF significantly differed from the CAD patients without AF by the fibrosis area in all atrial zones. In patient groups with rheumatic heart disease and permanent AF, the microfocal, perivascular, perimuscular fibrosis, and “armour fibrosis” were found, as well. When comparing the consolidated groups with CAD and AF and RMVD and AF, significant difference in the fibrosis area was shown (p=0.008). The extent of atrial fibrosis was more significant in the rheumatic patients. Thus, in AF at the background of both AF and rheumatic heart disease, the microfocal, diffuse, perivascular, perimuscular fibrosis, and “armour fibrosis” are observed. The latter type of fibrosis is more pronounced in rheumatic subjects. The rheumatic patients are also characterized by a more disseminated coarse-fibred fibrosis and hyalinosis.

coronary artery disease, rheumatic heart disease, myocarditis, atrial fibrillation, autopsy, histological study, fibrosis, hyalinosis

1. Абрикосов А.И. Частная патологическая анатомия. Сердце и сосуды. М. - Ленинград: «Медгиз» 1940; 570.

2. Аминева Х.К., Митрофанова Л.Б. Номенклатура и атлас гистопатологии миокарда. Пособие для врачей под ред. проф. Г.Б. Ковальского. Санкт-Петербург. 1994; 8.

3. Митрофанова Л.Б., Аминева Х.К. Ишемическая болезнь сердца (рабочие стандарты патологоанатомического исследования). СПб ГУЗ «ГПАБ». 2007; 61.

4. Mahrholdt H., Wagner A., Deluigi C. et al. Presentation, Patterns of Myocardial Damage, and Clinical Course of Viral Myocarditis // Circulation. 2006; 114: 1581-90.

5. Митрофанова Л.Б., Аминева Х.К., Александров К.Ю., Гордеев М.Л. Морфологическая диагностика ишемической болезни сердца и осложнений корригирующих операций. Пособие для врачей под ред. проф. Г.Б. Ковальского. Санкт-Петербург. 1999; 50.

6. Струков А.И., Бегларян А.Г. Патологическая анатомия и патогенез коллагеновых болезней. М.: гос. изд. мед. лит. 1963; 322.

7. Braunwald E. Heart Disease. A Textbook of Cardiovascular Medicine. Philadelphia. 1988; 1200.

8. Митрофанова Л.Б., Карев В.Е. Миокардиты Стандарты морфологической диагностики при аутопсии и эндомиокардиальной биопсии. СПб. 2010; 50.

9. Целуйко В.И., Дмитриев С.Ю. Роль интерстициального фиброза как предиктора возникновения фибрилляции предсердий. Медицина неотложных состояний. 2007; 3 (10): 124-126.

10. Everett IV T.H., Olgin J.E. Atrial fibrosis and the mechanisms of Atrial Fibrillation // Heart Rhythm. 2007; 4(3 Suppl): 24-27

11. Friedrichs K., Baldus S., Klinke A. Fibrosis in Atrial Fibrillation - Role of Reactive Species and MPO // J Mol Cell Cardiol. 2010; 48(3): 461-467.

12. Nguyen B.L., Fishbein M.C., Chen L.S. et al. Histopathological Substrate for Chronic Atrial Fibrillation in Humans // Heart Rhythm. 2009; 6(4): 454-460

13. on R.C., Sheikh F. Extracellular Matrix Remodeling in Atrial Fibrosis: Mechanisms and Implications in Atrial Fibrillation // J. Mol Cell Cardiol. 2010; 48(3): 461-467.

14. Wang Z., Lu Y., Yang B. MicroRNAs and atrial fibrillation: new fundamentals // Cardiovasc Res 2011; 89:710-721.

15. Frustaci A., Chimenti C., Belloci F. et al. Histological Substrate of Atrial Biopsies in Patients with Lone Atrial Fibrillation // Circulation. 1997; 96:1180-1184.

16. Psychari S.N., Apostolou T.S., Sinos L. et al. Relation of elevated C-reactive protein and interleukin-6 levels to left atrial size and duration of episodes in patients with atrial fibrillation // Am J Cardiol. 2005; 95: 764-767.

17. Chen M.-Ch., Chang J.-P., Liu W.-H. et al. Increased inflammatory cell infiltration in the Atrial Myocardium of Patients with Atrial Fibrillation // Am J Cardiol. 2008; 102:861-865.

18. Nakamura Y., Nakamura K., Fukushima-Kusano K. et al. Tissue factor expression in atrial endothelia associated with nonvalvular atrial fibrillation: possible involvement in intracardiac thrombogenesis // Thromb Res. 2003; 111: 137-142.

19. Yamashita T., Sekiguchi A., Iwasaki Y. et al. Recruitment of Immune Cells across Atrial Endocardium in Human Atrial Fibrillation // Circ J. 2010; 74: 262-270.

20. Митрофанова Л.Б., Ковальский Г.Б. Морфологические изменения миокарда при фибрилляции предсердий // Арх. Патологии. 2011; 73 (6): 10-15.

21. Platonov P.G., Mitrofanova L.B., V. Orshanskaya, S. Yen Ho. Structural abnormalities in atrial walls are associated with presence and persistency of atrial fibrillation but not with age // J Am College of Cardiol. 2011; 158 (21): 2226-2232.

22. Gramley F., Lorenzen J., Knackstedt Ch. et al. Age-related atrial fibrosis // Age (Dordr). 2009; 31(1): 27-38.

23. Burkauskiene A., Mackiewicz Z., Virtanen I., Konttinen Y.T. Age-related changes in myocardial nerve and collagen networks of the auricle of the right atrium // Acta Cardiol. 2006; 61(5): 513-8.

24. Debessa G.C.R., Maifrino M.L.B., de Souza R.R. Age related changes of the collagen network of the human heart // Mech Ageing Dev. 2001; 122(10): 1049-58.

25. Biernacka A., Frangogiannis N.G. Aging and Cardiac Fibrosis // Aging Dis. 2011; 2(2): 158-173.