title: Computational finite element model of cardiac torsion.
abstract: OBJECTIVE
  A novel finite-element model of ventricular torsion for the analysis of the twisting behavior of the left human ventricle was developed, in order to investigate the influence of various biomechanical parameters on cardiac kinematics.
  
  
  METHODS
  The ventricle was simulated as a thick-walled ellipsoid composed of nine concentric layers. Arrays of reinforcement bars were embedded in each layer to mimic physiological myocardial anisotropy. The reinforcement bars were activated through an artificial combination of thermal and mechanical effects in order to obtain a contractile behavior which is similar to that of myocardial fibers. The presence of an incompressible fluid inside the ventricular cavity was also simulated and the ventricle was combined with simple lumped-parameter hydraulic circuits reproducing preload and afterload. Changes to a number of cardiac parameters, such as preload, afterload and fiber angle orientation were introduced, in order to study the effects of these changes on cardiac torsion.
  
  
  RESULTS
  The model is able to reproduce a similar torsional behavior to that of a physiological heart. The results of the simulations showed that there was sound correspondence between the model outcomes and available data from the literature. Results confirmed the importance of symmetric transmural patterns for fiber orientation.
  
  
  CONCLUSIONS
  This model represents an important step on the path towards unveiling the complexity of cardiac torsion. It proves to be a practical and versatile tool which could assist clinicians and researchers by providing them with easily-accessible, detailed data on cardiac kinematics for future diagnostic and surgical purposes.
authors.affiliation: Laboratory of Biological Structure Mechanics, Structural Engineering Department, Politecnico di Milano, Milan - Italy. paola.bagnoli@polimi.it
authors.forename: Paola
authors.initials: P
authors.lastname: Bagnoli
authors.forename: Nicolò
authors.initials: N
authors.lastname: Malagutti
authors.forename: Dario
authors.initials: D
authors.lastname: Gastaldi
authors.forename: Emanuela
authors.initials: E
authors.lastname: Marcelli
authors.forename: Enrico
authors.initials: E
authors.lastname: Lui
authors.forename: Laura
authors.initials: L
authors.lastname: Cercenelli
authors.forename: Maria Laura
authors.initials: ML
authors.lastname: Costantino
authors.forename: Gianni
authors.initials: G
authors.lastname: Plicchi
authors.forename: Roberto
authors.initials: R
authors.lastname: Fumero
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D003198:Computer Simulation; D020342:Finite Element Analysis; D006801:Humans; D008955:Models, Cardiovascular; D009716:Numerical Analysis, Computer-Assisted; D012399:Rotation; D012756:Sheep; D013997:Time Factors; D016277:Ventricular Function, Left