Zinan Hu

All Publications

• Investigation of a chronic single-stage sheep Fontan model. JTCVS open Kelly, J. M., Hu, Z., Takaesu, F., Watanabe, T., Storrs, J., Blais, B., Yuhara, S., Morrison, A., Nelson, K., Ulziibayar, A., Heuer, E., Anderson, C., Jimenez, M., Leland, J., Malbrue, R., Arsuaga-Zorrilla, C., Goodchild, L., Naguib, A., McKee, C., Varner, J., DeShetler, C., Spiess, J., Harrison, A., Boe, B., Armstrong, A. K., Salavitabar, A., Hor, K., Krishnamurthy, R., Yates, A. R., Shinoka, T., Carrillo, S. A., Davis, M. E., Marsden, A. L., Breuer, C. K. 2024; 21: 268-278

  Abstract

  Our goal was to conduct a hemodynamic analysis of a novel animal model of Fontan physiology. Poor late-term outcomes in Fontan patients are believed to arise from Fontan-induced hemodynamics, but the mechanisms remain poorly understood. Recent advances in surgical experimentation have resulted in the development of a chronic sheep model of Fontan physiology; however, detailed analysis of this model is lacking.We created a single-stage Fontan model in juvenile sheep with normal biventricular circulation. The superior vena cava was anastomosed to the main pulmonary artery, and the inferior vena cava was connected to the main pulmonary artery using an expanded polytetrafluoroethylene conduit. Longitudinal hemodynamics, including catheterization and magnetic resonance imaging were evaluated.Four out of 12 animals survived, with the longest surviving animal living 3 years after single-stage Fontan. We showed a significant era effect regarding survival (1 out of 8 and subsequently 3 out of 4 animals surviving beyond 2 months) attributed in large part to the procedural learning curve. Key characteristics of Fontan hemodynamics, namely systemic venous hypertension and low normal cardiac output, were observed. However, recapitulation of passive human Fontan hemodynamics is affected by volume loading of the right ventricle given an anatomic difference in sheep azygous venous anatomy draining to the coronary sinus.A significant learning curve exists to ensure long-term survival and future surgical modifications, including banding of the main pulmonary artery and ligation of the azygous to coronary sinus connection are promising strategies to improve the fidelity of model hemodynamics.

  View details for DOI 10.1016/j.xjon.2024.06.018

  View details for PubMedID 39534321

  View details for PubMedCentralID PMC11551305

• Cardiovascular fluid dynamics: a journey through our circulation FLOW Menon, K., Hu, Z., Marsden, A. L. 2024; 4

  View details for DOI 10.1017/flo.2024.5

  View details for Web of Science ID 001221235200001

• IMPACT OF CARDIAC FIBER ORIENTATION ON ELECTRICAL DYSSYNCHRONY IN VENTRICULAR ECTOPY Perkins, S. J., Salvador, M., Hu, Z., Tikenogullari, O., Kong, F., Narayan, S. M., Marsden, A. ELSEVIER SCIENCE INC. 2024: 88

  View details for Web of Science ID 001291434300089

• A Modular Framework for Implicit 3D-0D Coupling in Cardiac Mechanics. Computer methods in applied mechanics and engineering Brown, A. L., Salvador, M., Shi, L., Pfaller, M. R., Hu, Z., Harold, K. E., Hsiai, T., Vedula, V., Marsden, A. L. 2024; 421

  Abstract

  In numerical simulations of cardiac mechanics, coupling the heart to a model of the circulatory system is essential for capturing physiological cardiac behavior. A popular and efficient technique is to use an electrical circuit analogy, known as a lumped parameter network or zero-dimensional (0D) fluid model, to represent blood flow throughout the cardiovascular system. Due to the strong physical interaction between the heart and the blood circulation, developing accurate and efficient numerical coupling methods remains an active area of research. In this work, we present a modular framework for implicitly coupling three-dimensional (3D) finite element simulations of cardiac mechanics to 0D models of blood circulation. The framework is modular in that the circulation model can be modified independently of the 3D finite element solver, and vice versa. The numerical scheme builds upon a previous work that combines 3D blood flow models with 0D circulation models (3D fluid - 0D fluid). Here, we extend it to couple 3D cardiac tissue mechanics models with 0D circulation models (3D structure - 0D fluid), showing that both mathematical problems can be solved within a unified coupling scheme. The effectiveness, temporal convergence, and computational cost of the algorithm are assessed through multiple examples relevant to the cardiovascular modeling community. Importantly, in an idealized left ventricle example, we show that the coupled model yields physiological pressure-volume loops and naturally recapitulates the isovolumic contraction and relaxation phases of the cardiac cycle without any additional numerical techniques. Furthermore, we provide a new derivation of the scheme inspired by the Approximate Newton Method of Chan (1985), explaining how the proposed numerical scheme combines the stability of monolithic approaches with the modularity and flexibility of partitioned approaches.

  View details for DOI 10.1016/j.cma.2024.116764

  View details for PubMedID 38523716

  View details for PubMedCentralID PMC10956732

• Computational approaches for mechanobiology in cardiovascular development and diseases. Current topics in developmental biology Brown, A. L., Sexton, Z. A., Hu, Z., Yang, W., Marsden, A. L. 2024; 156: 19-50

  Abstract

  The cardiovascular development in vertebrates evolves in response to genetic and mechanical cues. The dynamic interplay among mechanics, cell biology, and anatomy continually shapes the hydraulic networks, characterized by complex, non-linear changes in anatomical structure and blood flow dynamics. To better understand this interplay, a diverse set of molecular and computational tools has been used to comprehensively study cardiovascular mechanobiology. With the continual advancement of computational capacity and numerical techniques, cardiovascular simulation is increasingly vital in both basic science research for understanding developmental mechanisms and disease etiologies, as well as in clinical studies aimed at enhancing treatment outcomes. This review provides an overview of computational cardiovascular modeling. Beginning with the fundamental concepts of computational cardiovascular modeling, it navigates through the applications of computational modeling in investigating mechanobiology during cardiac development. Second, the article illustrates the utility of computational hemodynamic modeling in the context of treatment planning for congenital heart diseases. It then delves into the predictive potential of computational models for elucidating tissue growth and remodeling processes. In closing, we outline prevailing challenges and future prospects, underscoring the transformative impact of computational cardiovascular modeling in reshaping cardiovascular science and clinical practice.

  View details for DOI 10.1016/bs.ctdb.2024.01.006

  View details for PubMedID 38556423