Impact of mechanical and fluid mechanisms in the development and severity of pulmonary hypertension

Abstract

Pulmonary hypertension (PH) has become a global health issue that presents multiple factors involved in its development. This complexity induces difficulties for diagnosis and monitoring, leading up to a 47% of imprecise diagnosis. These events caused that in recent years multiple studies were developed looking for different and more precise diagnosis techniques, especially while using a non-invasive technique as transthoracic echocardiogram . These studies propose that the main pulmonary artery flow waveform can reflect the PH severity and PH origin, depending on flow profile pattern, timing, and flow values. This study was proposed to try to understand which are the mechanisms involved in these flow profile alterations by using pulmonary circulation computational models. Two scenarios were proposed: a 0D lumped model and a 3D fluid-structure interaction (FSI) model, where, by changing hemodynamic properties, like artery’s wall thickness, Young’s modulus or distal vascular bed resistance or compliance, the possible mechanisms involved on pulmonary artery flow waveform alterations will be analysed. Results reflected a higher impact on pressure increment by distal vascular resistance, meanwhile, proximal impedance, compliance, elasticity or wall thickness induce slight waveform alterations on pressure and flow profiles. However, the main pulmonary artery flow patterns observed during clinical routine were not replicated by the different computational models, suggesting that models proposed need further improvements on flow and pressure wave propagation in order to recreate, more precisely, all possible mechanisms involved in PH.