Abstract #0816

Measuring Changes in Morphology, Hemodynamics, and Mechanical Function by Controlling Ventricular Preload Using an MRI-Compatible Lower Body Negative Pressure Chamber

June Cheng Baron¹, Jessica Scott², Ben Esch², Kelvin Chow¹, Ian Paterson³, Mark Haykowsky⁴, Richard Thompson¹

¹Biomedical Engineering, University of Alberta, Edmonton, AB, Canada; ²Cardiovascular Physiology and Rehabilitation Laboratory, University of British Columbia, Vancouver, BC, Canada; ³Division of Cardiology, University of Alberta, Edmonton, AB, Canada; ⁴Physical Therapy, University of Alberta, Edmonton, AB, Canada

Cardiac performance is modulated in part by ventricular preload, which is determined largely by venous return to the heart and ventricular compliance. We illustrate control of preload using a custom MRI-compatible lower body negative pressure chamber to control venous return. Using standard cines, phase contrast and tissue tagging we measured ventricular volumes, hemodynamics and tissue mechanics at atmospheric (control) and -30 mmHg lower-body pressure (unloading similar to standing). We found significant changes in end-diastolic volumes, stroke volume, blood velocities, intraventricular pressure gradients, torsion and tissue velocity and strain rates, showing effective control of loading in a comprehensive cardiac MRI exam.