title: Flow dynamics and energy efficiency of flow in the left ventricle during myocardial infarction.
abstract: Cardiovascular disease is a leading cause of death worldwide, where myocardial infarction (MI) is a major category. After infarction, the heart has difficulty providing sufficient energy for circulation, and thus, understanding the heart's energy efficiency is important. We induced MI in a porcine animal model via circumflex ligation and acquired multiple-slice cine magnetic resonance (MR) images in a longitudinal manner-before infarction, and 1 week (acute) and 4 weeks (chronic) after infarction. Computational fluid dynamic simulations were performed based on MR images to obtain detailed fluid dynamics and energy dynamics of the left ventricles. Results showed that energy efficiency flow through the heart decreased at the acute time point. Since the heart was observed to experience changes in heart rate, stroke volume and chamber size over the two post-infarction time points, simulations were performed to test the effect of each of the three parameters. Increasing heart rate and stroke volume were found to significantly decrease flow energy efficiency, but the effect of chamber size was inconsistent. Strong complex interplay was observed between the three parameters, necessitating the use of non-dimensional parameterization to characterize flow energy efficiency. The ratio of Reynolds to Strouhal number, which is a form of Womersley number, was found to be the most effective non-dimensional parameter to represent energy efficiency of flow in the heart. We believe that this non-dimensional number can be computed for clinical cases via ultrasound and hypothesize that it can serve as a biomarker for clinical evaluations.
authors.affiliation: Department of Biomedical Engineering, National University of Singapore, Singapore, Singapore.
authors.forename: Vivek
authors.initials: V
authors.lastname: Vasudevan
authors.affiliation: Department of Biomedical Engineering, National University of Singapore, Singapore, Singapore.
authors.forename: Adriel Jia Jun
authors.initials: AJJ
authors.lastname: Low
authors.affiliation: Translational Biomarkers, Merck Research Laboratories, MSD, Singapore, Singapore.
authors.forename: Sarayu Parimal
authors.initials: SP
authors.lastname: Annamalai
authors.affiliation: Translational Biomarkers, Merck Research Laboratories, MSD, Singapore, Singapore.
authors.forename: Smita
authors.initials: S
authors.lastname: Sampath
authors.affiliation: Department of Cardiology, Yong Loo Lin School of Medicine, National University of Singapore, National University Health Systems, Singapore, Singapore.
authors.forename: Kian Keong
authors.initials: KK
authors.lastname: Poh
authors.affiliation: Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, National University Health Systems, Singapore, Singapore.
authors.forename: Teresa
authors.initials: T
authors.lastname: Totman
authors.affiliation: Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, National University Health Systems, Singapore, Singapore.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Mazlan
authors.affiliation: Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, National University Health Systems, Singapore, Singapore.
authors.forename: Grace
authors.initials: G
authors.lastname: Croft
authors.affiliation: Cardiovascular Research Institute, National University Heart Centre, Singapore, Singapore.|The Christchurch Heart Institute, University of Otago, Dunedin, New Zealand.
authors.forename: A Mark
authors.initials: AM
authors.lastname: Richards
authors.affiliation: Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, National University Health Systems, Singapore, Singapore.
authors.forename: Dominique P V
authors.initials: DPV
authors.lastname: de Kleijn
authors.affiliation: Translational Biomarkers, Merck Research Laboratories, MSD, Singapore, Singapore.
authors.forename: Chih-Liang
authors.initials: CL
authors.lastname: Chin
authors.affiliation: Department of Biomedical Engineering, National University of Singapore, Singapore, Singapore. bieyapc@nus.edu.sg.
authors.forename: Choon Hwai
authors.identifier: http://orcid.org/0000-0003-2918-3077
authors.initials: CH
authors.lastname: Yap
mesh_terms: D000818:Animals; D003198:Computer Simulation; D004734:Energy Metabolism; D006352:Heart Ventricles / Q000503:physiopathology*; D057446:Hydrodynamics; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D009203:Myocardial Infarction / Q000503:physiopathology*; D013318:Stroke Volume; D034421:Sus scrofa
keywords: Cardiac flow energy efficiency; Dynamic mesh computational fluid dynamics; Intra-ventricular flow; Myocardial infarction