title: Left and right ventricular hemodynamic forces in healthy volunteers and elite athletes assessed with 4D flow magnetic resonance imaging.
abstract: Intracardiac blood flow is driven by hemodynamic forces that are exchanged between the blood and myocardium. Previous studies have been limited to 2D measurements or investigated only left ventricular (LV) forces. Right ventricular (RV) forces and their mechanistic contribution to asymmetric redirection of flow in the RV have not been measured. We therefore aimed to quantify 3D hemodynamic forces in both ventricles in a cohort of healthy subjects, using magnetic resonance imaging 4D flow measurements. Twenty five controls, 14 elite endurance athletes, and 2 patients with LV dyssynchrony were included. 4D flow data were used as input for the Navier-Stokes equations to compute hemodynamic forces over the entire cardiac cycle. Hemodynamic forces were found in a qualitatively consistent pattern in all healthy subjects, with variations in amplitude. LV forces were mainly aligned along the apical-basal longitudinal axis, with an additional component aimed toward the aortic valve during systole. Conversely, RV forces were found in both longitudinal and short-axis planes, with a systolic force component driving a slingshot-like acceleration that explains the mechanism behind the redirection of blood flow toward the pulmonary valve. No differences were found between controls and athletes when indexing forces to ventricular volumes, indicating that cardiac force expenditures are tuned to accelerate blood similarly in small and large hearts. Patients' forces differed from controls in both timing and amplitude. Normal cardiac pumping is associated with specific force patterns for both ventricles, and deviation from these forces may be a sensitive marker of ventricular dysfunction. Reference values are provided for future studies.NEW & NOTEWORTHYBiventricular hemodynamic forces were quantified for the first time in healthy controls and elite athletes (n = 39). Hemodynamic forces constitute a slingshot-like mechanism in the right ventricle, redirecting blood flow toward the pulmonary circulation. Force patterns were similar between healthy subjects and athletes, indicating potential utility as a cardiac function biomarker.
authors: Department of Clinical Physiology, Skane University Hospital, and Clinical Physiology, Department of Clinical Sciences, Lund University, Lund, Sweden.
authors: Per M
authors: http://orcid.org/0000-0002-2262-3562
authors: PM
authors: Arvidsson
authors: Department of Clinical Physiology, Skane University Hospital, and Clinical Physiology, Department of Clinical Sciences, Lund University, Lund, Sweden.
authors: Johannes
authors: http://orcid.org/0000-0002-3365-7282
authors: J
authors: Töger
authors: Department of Clinical Physiology, Skane University Hospital, and Clinical Physiology, Department of Clinical Sciences, Lund University, Lund, Sweden.
authors: Marcus
authors: http://orcid.org/0000-0002-9480-5250
authors: M
authors: Carlsson
authors: Department of Clinical Physiology, Skane University Hospital, and Clinical Physiology, Department of Clinical Sciences, Lund University, Lund, Sweden.|Physiotherapy, Department of Health Sciences, Lund University, Lund, Sweden.
authors: Katarina
authors: http://orcid.org/0000-0002-7250-6508
authors: K
authors: Steding-Ehrenborg
authors: Department of Engineering and Architecture, University of Trieste, Trieste, Italy; and.
authors: Gianni
authors: http://orcid.org/0000-0003-2886-7653
authors: G
authors: Pedrizzetti
authors: Department of Clinical Physiology, Skane University Hospital, and Clinical Physiology, Department of Clinical Sciences, Lund University, Lund, Sweden.|Faculty of Engineering, Department of Biomedical Engineering, Lund University, Lund, Sweden.
authors: Einar
authors: http://orcid.org/0000-0003-2848-3326
authors: E
authors: Heiberg
authors: Department of Clinical Physiology, Skane University Hospital, and Clinical Physiology, Department of Clinical Sciences, Lund University, Lund, Sweden; hakan.arheden@med.lu.se.
authors: Håkan
authors: http://orcid.org/0000-0002-6124-3159
authors: H
authors: Arheden
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D056352:Athletes; D002037:Bundle-Branch Block / Q000000981:diagnostic imaging* / Q000503:physiopathology; D002311:Cardiomyopathy, Dilated / Q000000981:diagnostic imaging* / Q000503:physiopathology; D016022:Case-Control Studies; D005260:Female; D056973:Four-Dimensional Computed Tomography; D064368:Healthy Volunteers; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D006439:Hemodynamics; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000503:physiopathology; D016277:Ventricular Function, Left; D016278:Ventricular Function, Right; D055815:Young Adult
keywords: cardiac magnetic resonance imaging; four-dimensional flow; physiology