O.S. Sychov, P.B. Romaniuk, A.O. Borodai, V.H. Hurianov The heart rate influence on the myocardial structural and functional state and intracardiac hemodynamics in patients with non-valvular permanent atrial fibrillation

The aim – to estimate changes of the myocardial structural and functional state and intracardiac hemodynamics in patients with non-valvular permanent atrial fibrillation (PAF) under treatment with β-blockers (BB), to determine the critical value of the heart rate being a negative predictor of the echocardiographic parameters during 6 month monitoring, to identify the preference for one of the HR control strategies.

Material and methods. 30 patients were included in this study. The duration of observation was 238.3±17.0 days, it consisted in 3 visits. Titration of the BB dose lasted 67.7±10.3 days (the interval between the first and second visits). Treatment with maximal or maximal tolerable dose of BB lasted 170.6±17.7 days (the interval between the second and final visits). During the follow-up period, echocardiography was performed twice – at 2 and 3 visits.

Results. During follow-up period significant changes were revealed, i.e. increase of LV end-diastolic dimension and its index in the general group and in women; of LV end-diastolic volume in women; the increase of LV mass index in the general group and in women; basal and transverse diameters of the RV and its area in diastole; pressure in the LA; early diastolic mitral in flow velocity and its relation to early diastolic mitral annular velocity; diameters of the PA and aorta root, mitral regurgitation. Correlation analysis revealed relationship between rate of mitral annular systolic velocity and the degree of severity of mitral regurgitation with the mean daily HR value according to 24 h Holter ECG. Along with lenient heart rate control after 6 months significant increase of the the interventricular septum thickness, basal RV diameter and PA diameter was observed; fractional change of the RV area decreased. At achievement of strict heart rate control fractional change of the RV area significantly increased compared to lenient one.

Conclusions. During follow-up period in patients with PAF we observed progression of LV diastolic dysfunction, heart valve dysfunction and increase of heart chambers, more significant in women, due to pressure overload. The median daily heart rate > 91 beats/min recorded during Holter ECG is a predictor of systolic function deterioration according to the tissue Doppler. Strict heart rate control has an advantage over the lenient one to improve the myocardial structural and functional state, the size and contractility of the right heart.

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