Application of impedance cardiographic ambulatory monitoring device for analysis of central hemodynamic variability in atrial fibrillation

The impedance cardiography ambulatory monitoring device, which enables continuous collection of ECG and central hemodynamics signals, was applied for evaluation of hemodynamic variability in 5 male patients with atrial fibrillation (56-78 yr.) and in 5 (control) healthy males (44-68 yr.) during day time and night hours. The coefficient of variations (used as an index of variability) was higher in patients for stroke volume (by 0.203, p<0.05, 0.227/spl plusmn/0.19 vs. 0.43/spl plusmn/020), cardiac output (0.19, p<0.05, 0.16/spl plusmn/0.08 vs. 0.35/spl plusmn/19), amplitude (0.22, p<0.02, 0.17/spl plusmn/0.09 vs. 0.39/spl plusmn/0.15) and was not different for ejection time (ET: 0.19/spl plusmn/0.05 vs. 0.21/spl plusmn/0.05), pre-ejection period (PEP: 0.22/spl plusmn/0.06 vs. 0.24/spl plusmn/0.08). It was concluded that the variability of SV is mainly caused by the changes in amplitude of the signal and the variation in ET has the smaller impact.