Evaluation of microcirculatory blood flow of various cardiac chambers in patients with aortic stenosis before and after repair depending on left ventricle ejection fraction

Intraoperative study was centered on microcirculatory blood flow (MCBF) in 56 patients with aortic stenosis of III-IV stage. MCBF was measured depending on ejection fraction (EF) of the left ventricle (LV) by using BLF-21 computer-based Doppler laser flowmeter (Transonic System Inc., USA), with the right and left heart examined before and after repair. Sonographic data allowed for determining a pressure gradient between the aorta and the left ventricle, as well as the latter's size. The patients were classified into 3 groups: 1st group included patients with high EF 74,4 ± 2,8 %, 2nd group - with mean EF 58,5 ± 8,0 %, 3rd group - with low EF 40,5 ± 3,2 % and 3 types of MCBF respectively. The 1st type of MCBF was characterized by an initially high blood flow before repair, with a homogeneous MCBF in all cardiac chambers after repair. The 2nd type of MCBF with an initially heterogeneous blood flow in the cardiac chambers before operation featured the preservation of the gradient between the auricle and the ventricles after repair. The 3rd type of MCBF was determined by an abnormality of MCBF both before and after aortic valve replacement, which was accompanied by the development of complications in 57 % of cases during early postoperative period.