Purpose. Studying of opportunities of cardiac MRI in imaging and measurement of the left atrium (LA) and pulmonary veins anatomy, as well as the relationship of these parameters with the presence of myocardial ventricular fibrosis, in patients directed to the surgical treatment of atrial fibrillation (AF).

Materials and methods. The modified MRI protocol was performed to 93 patients selected for carrying out surgical treatment of atrial fibrillation (AF). The MRI protocol included: the sequences short Spin-Echo TSE-T1, retro\prospective gradient Echo in the cine mode (CINE) in standard projections, bolus- tracking MR-angiography, and also post-contrast images of the delayed enhancement (MDE). The created protocol included assessment of dimensional orientation of heart, measurement of linear dimensions and volume of left atrial (LA), anatomy of pulmonary veins with three-dimensional reconstruction, diagnosis of existence and type of myocardial fibrosis of ventricles, and also visualization of left atrial appendage.

Results. According to MR-angiography the following variants of anatomy of pulmonary veins are diagnosed: common trunk (19 patients), additional veins (17 patients), collector mouth of at least one vein (46 patients). According to MDE – non coronary types of myocardial fibrosis of LV were diagnosed for 16 patients, 5 patients have changes corresponding to pools of coronary blood supply. Parameters of structural remodeling of LA (diameter of LA, indexed maximum volume LA\BSA) in this group of patients authentically exceeded those groups without presence of myocardial fibrosis of LV (p=0.03). Cases of thrombosis of LA appendage are not revealed.

Conclusion. The created protocol allows to carry out three-dimensional reconstruction of LA within one research, to estimate quantity, the sizes and anatomy of mouths of pulmonary veins, to calculate the volume of LA and to visualize its appendage, and also to diagnose fibrosis changes of LV myocardium. The received interrelation between extent of remodeling of LA and existence of fibrosis of LV can determine perspectives of cardiac MRI in risk assessment and forecasting of efficiency of accomplishment of surgical treatment.