Peter Agger1, Robert S Stephenson2,3, Halina Dobrzynski4, Andrew Atkinson4, Paul A Iaizzo5, Robert H Anderson6,7, Jonathan C Jarvis2, Sarah L Allan8, John B Partridge9, Jichao Zhao10, Henggui Zhang11, David H MacIver12,13. 1. Department of Cardiothoracic and Vascular Surgery, Deptartment of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark. 2. Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom. 3. School of Dentistry, The University of Central Lancashire, Preston, United Kingdom. 4. School of Medicine, University of Manchester, Manchester, United Kingdom. 5. Institute for Engineering in Medicine, Department of Surgery, University of Minnesota, Minneapolis, Minnesota. 6. Institute of Genetic Medicine, Newcastle University, Newcastle Upon Tyne, United Kingdom. 7. Division of Biomedical Sciences, University College London, London, United Kingdom. 8. Department of Cardiology, Taunton & Somerset Hospital, Taunton, United Kingdom. 9. Eurobodalla Unit, Rural Clinical School of the ANU College of Medicine, Biology & Environment, Batemans Bay, NSW, Australia. 10. Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand. 11. Biological Physics Group, School of Astronomy and Physics, University of Manchester, Manchester, United Kingdom. 12. Department of Cardiology, Taunton & Somerset Hospital, Taunton, United Kingdom. david.maciver@tst.nhs.uk. 13. Biological Physics Group, School of Astronomy and Physics, University of Manchester, Manchester, United Kingdom. david.maciver@tst.nhs.uk.
Abstract
BACKGROUND: The anatomical substrate for the mid-mural ventricular hyperechogenic zone remains uncertain, but it may represent no more than ultrasound reflected from cardiomyocytes orientated orthogonally to the ultrasonic beam. We sought to ascertain the relationship between the echogenic zone and the orientation of the cardiomyocytes. METHODS: We used 3D echocardiography, diffusion tensor imaging, and microcomputed tomography to analyze the location and orientation of cardiomyocytes within the echogenic zone. RESULTS: We demonstrated that visualization of the echogenic zone is dependent on the position of the transducer and is most clearly seen from the apical window. Diffusion tensor imaging and microcomputed tomography show that the echogenic zone seen from the apical window corresponds to the position of the circumferentially orientated cardiomyocytes. An oblique band seen in the parasternal view relates to cardiomyocytes orientated orthogonally to the ultrasonic beam. CONCLUSIONS: The mid-mural ventricular hyperechogenic zone represents reflected ultrasound from cardiomyocytes aligned orthogonal to the ultrasonic beam. The echogenic zone does not represent a space, a connective tissue sheet, a boundary between ascending and descending limbs of a hypothetical helical ventricular myocardial band, nor an abrupt change in cardiomyocyte orientation.
BACKGROUND: The anatomical substrate for the mid-mural ventricular hyperechogenic zone remains uncertain, but it may represent no more than ultrasound reflected from cardiomyocytes orientated orthogonally to the ultrasonic beam. We sought to ascertain the relationship between the echogenic zone and the orientation of the cardiomyocytes. METHODS: We used 3D echocardiography, diffusion tensor imaging, and microcomputed tomography to analyze the location and orientation of cardiomyocytes within the echogenic zone. RESULTS: We demonstrated that visualization of the echogenic zone is dependent on the position of the transducer and is most clearly seen from the apical window. Diffusion tensor imaging and microcomputed tomography show that the echogenic zone seen from the apical window corresponds to the position of the circumferentially orientated cardiomyocytes. An oblique band seen in the parasternal view relates to cardiomyocytes orientated orthogonally to the ultrasonic beam. CONCLUSIONS: The mid-mural ventricular hyperechogenic zone represents reflected ultrasound from cardiomyocytes aligned orthogonal to the ultrasonic beam. The echogenic zone does not represent a space, a connective tissue sheet, a boundary between ascending and descending limbs of a hypothetical helical ventricular myocardial band, nor an abrupt change in cardiomyocyte orientation.
Authors: P P Lunkenheimer; P Niederer; J M Lunkenheimer; H Keller; K Redmann; M Smerup; R H Anderson Journal: Herz Date: 2018-07-27 Impact factor: 1.443
Authors: Robert S Stephenson; Peter Agger; Camilla Omann; Damian Sanchez-Quintana; Jonathan C Jarvis; Robert H Anderson Journal: J Cardiovasc Dev Dis Date: 2018-06-20