Model for RT-RR variability interaction assessment

A parametric dynamic model to evaluate the dependence of the ventricular repolarization duration on the heart period and on different not measurable inputs is proposed. Its parameters were identified from the beat-to-beat series of the cardiac cycle duration (RR interval) and ventricular repolarization period (RT period). Indexes relevant to the RT-RR relationship both in time and in frequency domain were extracted and validated in human subjects during experimental conditions known to alter the RT-RR coupling and/or sympatho-vagal balance.