title: Intraventricular flow patterns and stasis in the LVAD-assisted heart.
abstract: Left ventricular assist device (LVAD) support disrupts the natural blood flow path through the heart, introducing flow patterns associated with thrombosis, especially in the presence of medical devices. The aim of this study was to quantitatively evaluate the flow patterns in the left ventricle (LV) of the LVAD-assisted heart, with a focus on alterations in vortex development and stasis. Particle image velocimetry of a LVAD-supported LV model was performed in a mock circulatory loop. In the Pre-LVAD flow condition, a vortex ring initiating from the LV base migrated toward the apex during diastole and remained in the LV by the end of ejection. During LVAD support, vortex formation was relatively unchanged although vortex circulation and kinetic energy increased with LVAD speed, particularly in systole. However, as pulsatility decreased and aortic valve opening ceased, a region of fluid stasis formed near the left ventricular outflow tract. These findings suggest that LVAD support does not substantially alter vortex dynamics unless cardiac function is minimal. The altered blood flow introduced by the LVAD results in stasis adjacent to the LV outflow tract, which increases the risk of thrombus formation in the heart.
authors.affiliation: Bioengineering Program, San Diego State University, Department of Mechanical Engineering, San Diego, CA 92182-1323, United States.
authors.forename: K
authors.initials: K
authors.lastname: Wong
authors.affiliation: Bioengineering Program, San Diego State University, Department of Mechanical Engineering, San Diego, CA 92182-1323, United States.
authors.forename: G
authors.initials: G
authors.lastname: Samaroo
authors.affiliation: Bioengineering Program, San Diego State University, Department of Mechanical Engineering, San Diego, CA 92182-1323, United States.
authors.forename: I
authors.initials: I
authors.lastname: Ling
authors.affiliation: Mechanical Circulatory Support, Cardiothoracic Surgery, Sharp Memorial Hospital, San Diego, CA 92182-1323, United States.
authors.forename: W
authors.initials: W
authors.lastname: Dembitsky
authors.affiliation: Mechanical Circulatory Support, Cardiothoracic Surgery, Sharp Memorial Hospital, San Diego, CA 92182-1323, United States.
authors.forename: R
authors.initials: R
authors.lastname: Adamson
authors.affiliation: Mechanical and Aerospace Engineering, U.C. San Diego, La Jolla, CA 92093-0411, United States; Institute for Engineering in Medicine, U.C. San Diego, La Jolla, CA 92093, United States.
authors.forename: J C
authors.initials: JC
authors.lastname: del Álamo
authors.affiliation: Bioengineering Program, San Diego State University, Department of Mechanical Engineering, San Diego, CA 92182-1323, United States. Electronic address: kmaynewm@mail.sdsu.edu.
authors.forename: K
authors.initials: K
authors.lastname: May-Newman
mesh_terms: D001021:Aortic Valve / Q000601:surgery*; D001696:Biomechanical Phenomena; D001775:Blood Circulation; D003198:Computer Simulation; D003971:Diastole; D004867:Equipment Design; D006321:Heart / Q000503:physiopathology*; D006352:Heart Ventricles / Q000503:physiopathology* / Q000601:surgery*; D006353:Heart-Assist Devices; D006439:Hemodynamics; D006801:Humans; D007700:Kinetics; D008955:Models, Cardiovascular; D013599:Systole; D013718:Tensile Strength
keywords: Left ventricle; Mechanical circulatory assist; PIV; Thrombus; Vortex