One-dimensional haemodynamic modeling and wave dynamics in the entire adult circulation

One-dimensional (1D) modeling is a powerful tool for studying haemodynamics; however, a comprehensive 1D model representing the entire cardiovascular system is lacking. We present a model that accounts for wave propagation in anatomically realistic systemic (including coronary and cerebral) arterial/venous networks, pulmonary arterial/venous networks and portal veins. A lumped parameter (0D) heart model represents cardiac function via a time-varying elastance and source resistance, and accounts for mechanical interactions between heart chambers mediated via pericardial constraint, the atrioventricular septum and atrioventricular plane motion. A non-linear windkessel-like 0D model represents microvascular beds, while specialized 0D models are employed for the hepatic and coronary beds. Model-derived pressure and flow waveforms throughout the circulation are shown to reproduce the characteristic features of published human waveforms. Moreover, wave intensity profiles closely resemble available in vivo profiles. Forward and backward wave intensity is quantified and compared along major arteriovenous paths, providing insights into wave dynamics in all of the major physiological networks. Interactions between cardiac function/mechanics and vascular waves are investigated. The model will be an important resource for studying the mechanics underlying pressure/flow waveforms throughout the circulation, along with global interactions between the heart and vessels under normal and pathological conditions.