Gene Expression of Atrial Calcium - Handling Proteins in Patients with Rheumatic Heart Disease and Atrial Fibrillation

Objectives To investigate the gene expression of calcium - handling proteins in patients with rheumatic heart disease (RHD) and atrial fibrillation (AF) . Methods A total of 50 patients with rheumatic mitral valve disease were included. According to cardiac rhythm and duration of episode of AF, patients were divided into four groups: sinus rhythm group, paroxysmal AF group, persistent AF for less than 6 months group and persistent AF for more than 6 months group. Atrial tissue was obtained from the right atrial appendage, the right atrial free wall and the left atrial appendage respectively during open heart surgery. Total RNA was isolated and reversly transcribed into cDNA. In a semi - quantitative polymerase chain reaction the cDNA of interest and of glyceralde-hyde3 - phosphate dehydrogenase (GAPDH) were amplified and separated by ethidium bromide - stained gel electrophoresis. Multiple liner regress was used for correlation between the mRNA amount and age, sex, right atrial diameter (RAd) and left atrial diameter (LAd) . Results The mRNA of L - type calcium channeled subunit, of Ca2+ - ATPase and of ryanodine receptor in patients with persistent AF for more than 6 months were significantly decreased ( P all 0. 01) . But no alterations of the mRNA levels for SR phos-pholamban and calsequestrin were observed in patients with persistent AF for more than 6 months compared with patients with sinus rhythm, paroxysmal AF and persistent AF for less than 6 months ( P all 0. 05) . There was no difference of the gene expression among the three atrial tissue sampling sites (P all 0. 05) . Age, gender, RAd and LAd had no significant effects on the gene expression of calcium - handling proteins (P all0. 05). Conclusions The mRNA expression of calcium - handling proteins is down - regulated only in patients with RHD and long - term persistent AF. Such abnormalities may be related to the initiation and/or perpetuation of AF in the patients with RHD.