Integral pulse frequency modulation model driven by sympathovagal dynamics: Synthetic vs. real heart rate variability

• Published in: Biomedical signal processing and control Vol. 68; p. 102736
• Main Authors: Candia-Rivera, Diego, Catrambone, Vincenzo, Barbieri, Riccardo, Valenza, Gaetano
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.07.2021
• Subjects: Brain-heart interplay; Heart-rate variability; Integral pulse frequency modulation; Parasympathetic activity; Sympathetic activity; Sympathovagal modulation; Integral pulse frequency modulation; Sympathetic activity; Sympathovagal modulation; Brain-heart interplay; Parasympathetic activity; Heart-rate variability
• ISSN: 1746-8094; 1746-8108
• DOI: 10.1016/j.bspc.2021.102736

•The proposed IPFM model accurately generates synthetic RR intervals series with cardiac sympathetic and vagal dynamics as inputs.•The model tracks dynamical changes in heartbeat dynamics in different autonomic states including rest and postural changes.•Real and synthetic RR intervals do not differ statistically, and the proposed model improves on the standard IPFM model. Computational models that generate synthetic heart rate variability (HRV) series constitute important tools for the assessment of the effect of autonomic nervous system activity on cardiovascular control, and for the evaluation of novel algorithms using synthetic data. A widely used technique for synthetic HRV generation is the integral pulse frequency modulation (IPFM) model; however, IPFM relies on the HRV spectral paradigm, which cannot separate sympathetic and vagal oscillations that are overlapped in the low-frequency band (0.04–0.15 Hz). To overcome this limitation, a novel IPFM-inspired model driven by cardiac sympathetic and vagal dynamics estimated from HRV is proposed, where our recently developed sympathetic and parasympathetic activity indices that rely on orthonormal Laguerre expansions of the RR interval autoregressive kernels are exploited. The performance of the proposed model is evaluated by comparing the synthetic vs. real RR interval series in a simulation study involving postural changes, with real HRV data gathered from 10 healthy subjects. Moreover, the performance of the proposed model is compared with that of the standard IPFM to discern different autonomic control states associated with resting and postural changes. The results confirm that the proposed physiologically inspired model adequately predicts RR intervals during resting and postural changes. The proposed model clearly outperforms the standard IPFM method, considering both median error, and maximum error. The developed model provides valuable insights for a better understanding of the sympathovagal activity in the analysis of heartbeat dynamics.