Atrial fibrillation (AF) is the most common type of heart arrhythmia, which increases the risks of death, stroke and other thromboembolic complications. [1] Stasis in the left atrium (LA) flow is regarded as one of the main factors of thrombus formation in AF patient. (2) However, the knowledge of hemodynamic changes in AF remains rather limited. 4D flow MRI is a novel, currently available non-contrast technique of multidirectional blood flow assessment. 3D cine velocity encoding acquisitionprovides data of complete time-resolved 3-directional velocity field to complex...

Patient population In this retrospective study, 15 patients were included: 8 healthy volunteers (28±11 years) and 7 patients with supraventricular arrhythmias, paroxysmal form, in sinus rhythm (35±8.5 years). MRI protocol All patients were studied with a 1.5 T MRI. Cine 3D velocity-encoding acquisition was performed covering LA with ECG-gating. Scanning parameters were: TR: 75-80ms; TE: 3,36ms; FA: 15°; venc: 80ms, spatial resolution: 2,2x1,7x5mm. Data Analysis 4D flow data were post-processed using 4D Flow version 2.4 (Siemens). All 4 PVs ostia were selected at 3D model...

Quantification of the PVs flow. 32 PVs in the CG and 27 of PVs in AFG were analyzed. Hemodynamic parameters of the PVs flow except for the Average flow rate decreased significantly in AFG. (Tab. 1) Table 1. Quantification of the PVs flow in controls and AF patient. Average volume flow rate (ml/s) Peak volume flow rate (ml/s) Forward volume (ml) Peak velocity (сm/s) CG (n=32) 19,40 (15,70; 24,40) 40,86 (32,39; 51,02) 18,24 (13,73; 20,97) 41,38 (36,10; 53,73) AFG (n=27) 18,00 (10,00; 23,87) 30,00 (18,60;...

4D Flow MRI revealed significant changes in AF patients flow. PVs hemodynamics patterns were reduced (p<0,05), PVs flow were desynchronized, and LA vortex was rarely formed (p<0.05). Further evaluation was required to estimate diagnostic value of these criteria as risk factors for thromboembolic complications.

1.ACC/AHA/ESC 2006 Guidelines for the management of patients with atrial fibrillation. Europace. 2006; (8): 651-745. 2.Watson T., Shantsila E., Lip G.Y. Mechanisms of thrombogenesis in atrial fibrillation: Virchow’s triad revisited. Lancet. 2009; 373: 155–166. 3.Fyrenius А., Wigström L., Ebbers T., Karlsson M., Engvall J., Bolger A.F. Three dimensional flow in the human left atrium. Heart. 2001; 86: 448–455 4.Suwa K., Saito T., Sano M., Nobuhara M., Saotome M., Urushida T., Katoh H., Satoh H. Vortex imaging in the left atrium generated by pulmonary venous inflow...