Polycythaemia vera is a blood disorder caused by increased blood cells and associated with further complications, such as hypertension, thrombotic events or ocular problems. This study aims to evaluate the haemodynamic consequences of polycythaemia vera with and without hypervolemia using numerical modelling. A numerical model simulating cardiac function, systemic, pulmonary and cerebral circulations, cerebral autoregulatory function, cerebrovascular O2 and CO2 reactivities, and baroreflex regulation of systemic arteriolar resistance was proposed to simulate cardiac function and cerebral blood flow rate in polycythaemia with and without hypervolemia. Also, a novel model describing the regulation of systemic arteriolar resistance according to the haemoglobin levels in blood was developed and integrated into the computational model to simulate the effects of the haemoglobin in blood on the pressure and flow rate of blood circulation. The computational model was used to simulate a healthy case and polycythaemia vera with and without hypervolemia by modifying the blood haemoglobin level, total blood volume and arterial compliances. Simulation results showed that polycythaemia vera increases the blood pressure in the systemic and cerebral arteries, whereas hypervolemia causes a further increase, inducing hypertension. Although polycythaemia vera reduced the cardiac output, hypervolemia increased it profoundly. Polycythaemia vera reduced the cerebral flow rate profoundly, and hypervolemia reduced it further, causing a compromised blood flow rate in the cerebral circulation. Polycythaemia vera affects the cardiac function and cerebral blood flow rate. Also, hypervolemia may increase the risk of complications.
Bozkurt et al. (Mon,) studied this question.