Computer models for studying interventions used in treating refractory pulmonary hypertension.

This paper describes computer models for three palliations used in treating refractory pulmonary hypertension. These procedures effectively create an atrial septal defect, a ventricular septal defect, or a patent ductus arteriosus, also known as a Potts shunt. The aim in all three cases is to generate a right-to-left shunt, allowing for either pressure or volume unloading of the right side of the heart in the setting of right ventricular failure, while allowing for maintenance of cardiac output. However, these shunts are created at the expense of introducing de-oxygenated blood into the systemic circulation, thereby lowering the systemic arterial oxygen saturation. The models developed in this paper are based on compartmental descriptions of human hemodynamics and oxygen transport. An important parameter included in our models is the cross-sectional area of the surgically created defect. Numerical simulations are performed to compare different interventions and various shunt sizes and to assess their impact on hemodynamic variables and oxygen saturations.