Analysis of blood pressure and heart rate synchronization under non-stationary conditions

The feedback regulation of blood pressure and heart rate is an important indicator of human autonomic function. Here we suggest a method to evaluate its efficacy by detecting the epochs of synchronization and by determining their quantitative characteristics from the beat-to-beat data records. We assess the phases of both processes using Gilbert Transform and analyze the phase differences. By applying the proposed method to the tilt test records from different groups of patients as well as healthy individuals we obtained a significant difference (p <; 0.05) in the values of the synchronization coefficient. Our method is particularly useful for the data analysis under non-stationary conditions.