Intracardiac and systemic hemodynamic parameters in patients with atrial fibrillation and flutter associated to arterial hypertension depending on lymphocytes and monocytes subpopulation characteristics and composition in peripheral blood

Abstract

The aim – to compare intracardiac and systemic hemodynamic parameters in patients with paroxysmal and persistent forms of atrial fibrillation and atrial flutter associated with arterial hypertension, depending on the characteristics of peripheral blood lymphocyte and monocyte subpopulations.
Materials and methods. 147 patients were included into the study. Among them, 103 had atrial fibrillation or atrial flutter associated to arterial hypertension. Patients with rhythm disturbances were divided into three main groups: 
group I – paroxysmal atrial fibrillation; group II – persistent atrial fibrillation; group III – persistent atrial flutter. Peripheral blood levels of lymphocyte and monocyte subpopulations were assessed using flow cytometry. Hemodynamic parameters were evaluated via transthoracic echocardiography, office blood pressure measurements, 24-hour ambulatory blood pressure monitoring, and transesophageal echocardiography. As controls, data from patients with arterial hypertension but without arrhythmias and from practically healthy individuals were used, forming groups IV and V, respectively. 
Results and discussion. Analysis of lymphocyte subpopulations in groups I–III revealed that the absolute and relative numbers of cytotoxic cells (NK and NKT cells) were significantly higher compared with healthy individuals. A statistically significant reduction (p ≤ 0.05) in regulatory T-cell counts was observed in groups II and III comparing to controls. 
Patients with AF and AFL on the background of hypertension demonstrated an increased number of classical and intermediate monocyte fractions compared with hypertensive patients without rhythm disturbances and healthy subjects.
Comparison of echocardiographic parameters between groups I–III and group IV revealed statistically significant differences (p ≤ 0.05) in left ventricular linear dimensions (end-diastolic diameter, end-systolic diameter, interventricular septal thickness, posterior wall thickness), transverse dimensions of the left atrium and right ventricle, early-to-late left ventricular filling velocity ratio (E/A), and left ventricular mass indices. Compared with group V, significant differences were observed only in end-systolic diameter, left atrial size, interventricular septal thickness, and posterior wall thickness. Office systolic blood pressure values were markedly higher in patients with arrhythmias. According to 24-hour blood pressure monitoring, significant differences were found in mean and maximal diastolic pressure.
Conclusions. Patients with atrial fibrillation and atrial flutter associated to arterial hypertension, compared to individuals without arrhythmias or healthy people, present elevated levels of pro-inflammatory monocyte subpopulations, increased numbers of cytotoxic T cells, and reduced levels of regulatory T cells. Echocardiographic data indicate more pronounced structural myocardial changes in these patients, including larger left atrial and left ventricular dimensions, increased interventricular septal and posterior wall thickness, and diastolic dysfunction. Measured systolic and diastolic blood pressure values differed significantly, indicating hemodynamic disturbances attributable both to rhythm disorders and to manifestations of arterial hypertension.