Atrial fibrillation in pure rheumatic mitral valvular disease is expression of an atrial histological change.

Background: Some of theo- ries try to explain the insurgence of atrial fibrilla- tion (AF) in patients with acute articular rheuma- tism (AAR). These theories remind the close re- lation between AF and left atrium, or with valvu- lar vitium degree, or monophasic action poten- tial and histological cardiac structure. In 15 years of work in the academic Department of Heart and Big Vessels in Rome, the Authors studied 243 patients with mitral valvular disease post AAR before and after surgical manoeuvres. Materials and Methods: Patients were divid- ed in order to monitor atrium and ventricle mor- phological and functional modifications of the valve according to cardiac rhythm. Patients clas- sification was based on surgical therapy adopted, kind of mitral disease and cardiac rhythm. An his- tological examination was performed, only in pa- tients treated with valvular replacement. During the operation an histological examination in an atrial tissue fragment was performed. 243 pa- tients with mitral valvular disease post AAR with indication in valvular adjustment were studied. The whole population was treated with mitral transcutaneous valvuloplasty (Group B - 130 pa- tients) or with mitral valve replacement surgery (Group A - 113 patients). These two groups were divided: in Gr.A in Gr.A1 and Gr.A2, and Gr.B in Gr.B1 and Gr.B2, according to cardiac rhythm (si- nus rhythm iSR, AF). These subgroups were also divided in Gr.A 1SR, Gr.A 1AF; Gr.A 2SR, Gr.A 2AF; Gr.A3SR, Gr.A3AF, according to mitralic disease's kind (stenosis, stenosis/regurgitation, regurgita- tion). A complex screening were exerted to all pa- tients using echocardio-doppler technology. Mor- phological parameters of atrium and ventricle, and functional parameters of mitral valve, aorta and tricuspid were evaluated. In Gr.A group pa- tients during the operation were execute a bioptic sampling from left atrium and a consecutive his- tological valuation. Results: In Gr.A1 mitral valve area (MtVA) arises smaller (p<0.01) in the group with AF, than those in SR. On the contrary, in subgroups of population of Gr.B there isn't statistic dis-