The human cardiovascular system consists of two large arteries: the aorta (AO), which supplies oxygenated blood to the body, and the pulmonary artery (PA), which supplies deoxygenated blood to the lungs for oxygenation. In healthy individuals, the pressure in the AO is significantly higher than the pressure in the PA. Pulmonary artery hypertension (PAH) is a disease in which the PA pressure is abnormally elevated and is classified as one of the most devastating disorders by the pulmonary artery association UK. This is evidenced by a mean survival time after diagnosis of less than 30 months in adults and less than 12 months in children. A recently proposed treatment for severe PAH, i.e. the case when PA pressure is higher than the pressure in AO, is to create a connection, known as the Potts shunt, between the PA and the AO. Just as a connection between two pipes carrying fluids with high and low pressures will lead to a reduction of pressure in the high-pressure pipe and an increase of pressure in the low-pressure pipe, the idea is that a Potts shunt can lead to a reduction of PA pressure in severe PAH patients. This reduction in PA pressure is desirable but will also result in mixing of oxygenated and deoxygenated blood, an undesirable effect. Clinical experience has shown favourable results of this treatment in some patients and unfavourable in others, which is attributed largely to a reduction in cardiac output, the total volume of blood ejected by the heart in one cardiac cycle. This project aims to develop computational models to assess three measures of Potts shunt treatment: 1) reduction of pulmonary artery pressure, 2) mixing of oxygenated and deoxygenated blood, and 3) reduction in cardiac output. Through the computational models, this project will assess the mechanisms behind the success/failure of Potts shunt in relation to the above measures. The end-product will be a computer model which, given a new patient, can determine if a Potts shunt is likely to succeed in the patient. Furthermore, technology to optimise the design of Potts shunt for each patient individually, such that maximal clinical benefit is achieved, will be developed.