Collaborative Research: Changes and Impact of Right Ventricle Viscoelasticity Under Acute Stress and Chronic Pulmonary Hypertension

The failure of the right ventricle can indicate a higher risk of mortality in diseases like pulmonary hypertension and heart failure with preserved ejection fraction. People with these diseases often report exercise intolerance, which suggests that their response to physical stress is impaired. This research project aims to improve our understanding of the mechanical behavior of the right ventricle and how it affects its pumping function. The concept of viscoelasticity, which refers to the immediate (elastic) and delayed (viscous) resistance of cardiac tissue during contraction and relaxation, will be used to study how cellular behavior and the overall performance of the heart are affected. The research will include a comprehensive analysis of the viscoelasticity of the right ventricle tissue and its implications in organ function. The findings of this study could be used to the care and management of approximately 6.7 million heart failure patients, which are projected to increase with the aging population. The research team plans to engage young minds and advance the education of the next generation of bioengineers, with a focus on mentoring women and first-generation students to enhance diversity in the STEM workforce.

The aim of the research is to discover how the ventricle wall viscoelastic properties change under acute stress and chronic pulmonary hypertension and impact organ function. To characterize the tissue biaxial viscoelasticity with disease progression and at varied heart rates, the passive viscoelasticity of the right ventricle will be measured experimentally by stress relaxation and cyclical tensile tests and simulated computationally with our validated models. To reveal the cellular and extracellular components’ contributions to tissue viscoelasticity, drug treatment will be performed to depolymerize microtubules and degrade collagen and changes in tissue viscoelasticity will be quantified. A new multiscale constitutive model will be developed to predict the viscoelasticity of myofibers and collagen as well as collagen recruitment. Finally, organ function changes will be measured with right ventricle viscoelasticity altered by chronic hypertension and acute stress. Educational activities include the distribution of various STEM kits to elementary and middle-to-high school students in northern Colorado, participation in existing K-12 public outreach events on campus. Additionally, there will be training and mentoring of underrepresented undergraduate and graduate students.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

Award Number: 2547050
Principal Investigator: Zhijie Wang
Funds Obligated: $115,117
State: CA