title: Torsion of the human left ventricle: experimental analysis and computational modeling.
abstract: We set a twofold investigation: we assess left ventricular (LV) rotation and twist in the human heart through 3D-echocardiographic speckle tracking, and use representative experimental data as benchmark with respect to numerical results obtained by solving our mechanical model of the LV. We aim at new insight into the relationships between myocardial contraction patterns and the overall behavior at the scale of the whole organ. It is concluded that torsional rotation is sensitive to transmural gradients of contractility which is assumed linearly related to action potential duration (APD). Pressure-volume loops and other basic strain measures are not affected by these gradients. Therefore, realistic torsional behavior of human LV may indeed correspond to the electrophysiological and functional differences between endocardial and epicardial cells recently observed in non-failing hearts. Future investigations need now to integrate the mechanical model proposed here with minimal models of human ventricular APD to drive excitation-contraction coupling transmurally.
authors.affiliation: Dipartimento di Fisiopatologia Cardiocircolatoria, Anestesiologia e Chirurgia Generale, Università degli Studi di Roma "La Sapienza", viale del Policlinico 155, I-00166 Roma, Italy. antoevangelista@live.it
authors.forename: A
authors.initials: A
authors.lastname: Evangelista
authors.forename: P
authors.initials: P
authors.lastname: Nardinocchi
authors.forename: P E
authors.initials: PE
authors.lastname: Puddu
authors.forename: L
authors.initials: L
authors.lastname: Teresi
authors.forename: C
authors.initials: C
authors.lastname: Torromeo
authors.forename: V
authors.initials: V
authors.lastname: Varano
mesh_terms: D001696:Biomechanical Phenomena; D001794:Blood Pressure; D003198:Computer Simulation; D019560:Echocardiography, Three-Dimensional; D004699:Endocardium / Q000033:anatomy & histology / Q000166:cytology / Q000000981:diagnostic imaging / Q000502:physiology; D006352:Heart Ventricles / Q000033:anatomy & histology / Q000166:cytology / Q000000981:diagnostic imaging*; D006801:Humans; D008954:Models, Biological; D009929:Organ Size; D012399:Rotation; D013314:Stress, Mechanical; D013997:Time Factors; D016277:Ventricular Function, Left