Dr Olivier Bernus
BSc, MSc, PhD, Belgium
Tenure Track Independent Research Fellow
Institute of Membrane and Systems Biology
Background: BSc 1997 (Ghent, Belgium), MSc 1999 (Ghent, Belgium), PhD 2003 (Ghent, Belgium). Postdoctoral research, SUNY Upstate Medical University, USA (2004 ? 2006). Tenure-Track Independent Research Fellow, University of Leeds (2007?)
Office: Garstang 7.52a
Phone: +44(0) 113 34 34235
Email: o.bernus@leeds.ac.uk
Centre membership: The Multidisciplinary Cardiovascular Research Centre (MCRC)
Research Interests
Three-dimensional organization of cardiac electrical activity during arrhythmias
My research focuses on the mechanisms underlying life-threatening cardiac arrhythmias leading to sudden cardiac death, the largest cause of death in the industrialized world.
Every heartbeat is triggered by electrical waves of excitation propagating through the cardiac muscle from sinus node to the ventricles. Abnormal propagation of this wave severely compromises the mechanical function of the heart and represents a major cause of arrhythmias. Re-entry, during which a wave of excitation repeatedly activates the cardiac muscle, is such a type of abnormal propagation and occurs during dangerous arrhythmias such as fibrillation. My laboratory utilizes both computational and experimental techniques to visualize the propagation of electrical waves through myocardium and understand the mechanisms underlying re-entry and associated arrhythmias.
Depth-resolved optical imaging of cardiac electrical activity
Optical imaging using voltage-sensitive dyes has become a powerful tool to study electrical propagation in cardiac tissue. However, poor transparency of tissue has enforced surface or sub-surface imaging and prevents the use of conventional optical methods to visualize the electrical waves through the thickness of the cardiac muscle. My laboratory works on the application of novel optical tomographical methods and laser scanning to probe deeper layers of the cardiac muscle and unravel the three-dimensional wave patterns underlying cardiac arrhythmias.
Overseas collaborators: Prof. Arkady Pertsov (SUNY Upstate Medical University, USA) and Prof. Elizabeth Hillman (Columbia University, USA).
Arrhythmias due to acute myocardial ischemia
There is compelling clinical evidence that acute myocardial ischemia occurring after coronary occlusion is one of the most important causes of ventricular arrhythmias. Recently, we discovered a novel mechanism for arrhythmogenesis during early regional ischemia using a realistic computational model of ischemic myocardium. In this model, re-entry occurred as a result of calcium-mediated alternating conduction blocks in the ischemic border zone. Based on this hypothesis, we have designed an experimental model of regional ischemia and are currently investigating arrhythmogenesis in this model.
Overseas collaborator: Prof. Arkady Pertsov (SUNY Upstate Medical University, USA).
Cosmology in the heart
Scroll waves appear to be a common manifestation of functional re-entry in thick three-dimensional myocardium. Their dynamics have been found to be an important determinant of the severity of the arrhythmias that they underlie. From a theoretical point of view, the motion of scroll wave can be studied by focusing on their rotation centre, the so-called filaments. Such scroll wave filaments exhibit striking similarities to cosmic strings in the universe. Hence we can apply well-established mathematical techniques from cosmology to re-entrant arrhythmias in the heart. In such formalism, the cardiac fibrous structure translates naturally as a non-trivial metric on space. This way, we have been able to derive the full equation of motion of scroll wave filaments and are now investigating the effects of the heart’s fibrous structure.
Overseas collaborator: Prof. Henri Verschelde (Ghent University, Belgium).
Current Projects
- Three-dimensional optical imaging of cardiac electrical activity using alternating illumination. Engineering and Physical Sciences Research Council (EP/F065574/1), 01/11/2008 – 31/10/2011, £355505. PI: O. Bernus.
- Optical Tomography of cardiac electrical activity. The Royal Society, 01/06/2008 – 31/05/2009, £14460. PI: O. Bernus
- Dynamics of filaments in contracting anisotropic excitable media. The Research Foundation – FWO (Belgium), 01/10/2006 – 30/09/2010, PhD Fellowship to Hans Dierckx (Supervisors: Prof. H. Verschelde and Dr. O. Bernus).
- Integrative computational approach to the role of myocardial structure in myocardial function and dysfunction. Medical Research Council, 01/11/2008 – 30/04/2012, £422714, Special Research Training Fellowships in Biomedical Informatics to Stephen Gilbert (Supervisors: Dr. O. Bernus, Prof. A. Holden and Prof. E. White).
Publications
Gilbert SH; Benoist D; Benson AP; White E; Tanner SF; Holden AV; Dobrzynski H; Bernus O; Radjenovic A Visualization and quantification of whole rat heart laminar structure using high-spatial resolution contrast-enhanced MRI AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY 302 H287-H298, 2012
DOI:10.1152/ajpheart.00824.2011
Walton RD; Smith RM; Mitrea BG; White E; Bernus O; Pertsov AM Extracting Surface Activation Time from the Optically Recorded Action Potential in Three-Dimensional Myocardium BIOPHYSICAL JOURNAL 102 30-38, 2012
DOI:10.1016/j.bpj.2011.10.036
Benoist D; Stones R; Drinkhill MJ; Benson AP; Yang Z; Cassan C; Gilbert SH; Saint DA; Cazorla OF; Steele DS; Bernus O; White E Cardiac arrhythmia mechanisms in rats with heart failure induced by pulmonary hypertension. Am J Physiol Heart Circ Physiol -, 2012
DOI:10.1152/ajpheart.01084.2011
Clayton RH; Bernus O; Cherry EM; Dierckx H; Fenton FH; Mirabella L; Panfilov AV; Sachse FB; Seemann G; Zhang H Models of cardiac tissue electrophysiology: Progress, challenges and open questions PROGRESS IN BIOPHYSICS&MOLECULAR BIOLOGY 104 22-48, 2011
DOI:10.1016/j.pbiomolbio.2010.05.008
Benson AP; Bernus O; Dierckx H; Gilbert SH; Greenwood JP; Holden AV; Mohee K; Plein S; Radjenovic A; Ries ME; Smith GL; Sourbron S; Walton RD Construction and validation of anisotropic and orthotropic ventricular geometries for quantitative predictive cardiac electrophysiology INTERFACE FOCUS 1 101-116, 2011
DOI:10.1098/rsfs.2010.0005
Benoist D; Stones R; Drinkhill M; Bernus O; White E Arrhythmogenic substrate in hearts of rats with monocrotaline-induced pulmonary hypertension and right ventricular hypertrophy AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY 300 H2230-H2237, 2011
DOI:10.1152/ajpheart.01226.2010
Dierckx H; Bernus O; Verschelde H Accurate eikonal-curvature relation for wave fronts in locally anisotropic reaction-diffusion systems Physical Review Letters 107 -, 2011
Benson AP; Bernus O; Holden AV; Zhang H QUANTIFICATION OF SPATIAL DYNAMICS OF CARDIAC ARRHYTHMIAS, 2011
DOI:10.1136/hrt.2010.213496.17
Niederer SA; Kerfoot E; Benson AP; Bernabeu MO; Bernus O; Bradley C; Cherry EM; Clayton R; Fenton FH; Garny A; Heidenreich E; Land S; Maleckar M; Pathmanathan P; Plank G; Rodriguez JF; Roy I; Sachse FB; Seemann G; Skavhaug O; Smith NP Verification of cardiac tissue electrophysiology simulators using an N-version benchmark PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES 369 4331-4351, 2011
DOI:10.1098/rsta.2011.0139
Walton RD; Xavier CDL; Tachtsidis I; Bernus O; IEEE Experimental Validation of Alternating Transillumination for Imaging Intramural Wave Propagation 2011 ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY (EMBC) 1676-1679, 2011
Gilbert SH; Benson AP; Walton RD; Bernus O; IEEE Slowed Propagation Across the Compacta-Trabeculata Interface: A Consequence of Fiber and Sheet Anisotropy 2011 ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY (EMBC) 1688-1692, 2011
Myles RC; Bernus O; Burton FL; Cobbe SM; Smith GL Effect of activation sequence on transmural patterns of repolarization and action potential duration in rabbit ventricular myocardium AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY 299 H1812-H1822, 2010
DOI:10.1152/ajpheart.00518.2010
Walton RD; Benoist D; Hyatt CJ; Gilbert SH; White E; Bernus O Dual excitation wavelength epifluorescence imaging of transmural electrophysiological properties in intact hearts HEART RHYTHM 7 1843-1849, 2010
DOI:10.1016/j.hrthm.2010.08.019
Dierckx H; Benson AP; Gilbert SH; Ries ME; Holden AV; Verschelde H; Bernus O Intravoxel Fibre Structure of the Left Ventricular Free Wall and Posterior Left-Right Ventricular Insertion Site in Canine Myocardium Using Q-Ball Imaging, 2009
Walton RD; Bernus O; IEEE Computational Modeling of Cardiac Dual Calcium-Voltage Optical Mapping EMBC: 2009 ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY, VOLS 1-20 2827-2830, 2009
Bernus O; Holden AV; Panfilov AV Nonlinear waves in excitable media: Approaches to cardiac arrhythmias Preface PHYSICA D-NONLINEAR PHENOMENA 238 V-VIII, 2009
DOI:10.1016/S0167-2789(09)00119-5
Walton RD; Mitrea BG; Pertsov AM; Bernus O; IEEE A novel near-infrared voltage-sensitive dye reveals the action potential wavefront orientation at increased depths of cardiac tissue EMBC: 2009 ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY, VOLS 1-20 4523-4526, 2009
Dierckx H; Bernus O; Verschelde H A geometric theory for scroll wave filaments in anisotropic excitable media PHYSICA D-NONLINEAR PHENOMENA 238 941-950, 2009
DOI:10.1016/j.physd.2008.09.006
Walton RD; Bernus O; IEEE Electrotonic effects on action potential duration in perfused rat hearts EMBC: 2009 ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY, VOLS 1-20 4190-4193, 2009
Gilbert SH; Bernus O; Holden AV; Benson AP A Quantitative Comparison of the Myocardial Fibre Orientation in the Rabbit as Determined by Histology and by Diffusion Tensor-MRI, 2009
Hyatt CJ; Zemlin CW; Smith RM; Matiukas A; Pertsov AM; Bernus O Reconstructing subsurface electrical wave orientation from cardiac epi-fluorescence recordings: Monte Carlo versus diffusion approximation OPTICS EXPRESS 16 13758-13772, 2008
DOI:10.1364/OE.16.013758
Zemlin CW; Bernus O; Matiukas A; Hyatt CJ; Pertsov AM Extracting intramural wavefront orientation from optical upstroke shapes in whole hearts BIOPHYSICAL JOURNAL 95 942-950, 2008
DOI:10.1529/biophysj.107.117887
Benson AP; Hodgson EK; Bernus O; Holden AV; IEEE Quantifying the Effects of Ischaemia on Electrophysiology and the ST Segment of the ECG in Human Virtual Ventricular Cells and Tissues, 2008
Verschelde H; Dierckx H; Bernus O Covariant stringlike dynamics of scroll wave filaments in anisotropic cardiac tissue PHYSICAL REVIEW LETTERS 99 -, 2007
DOI:10.1103/PhysRevLett.99.168104
Hillman EMC; Bernus O; Pease E; Bouchard MB; Pertsov A Depth-resolved optical imaging of transmural electrical propagation in perfused heart OPTICS EXPRESS 15 17827-17841, 2007
DOI:10.1364/OE.15.017827
Bernus O; Mukund KS; Pertsov AM Detection of intramyocardial scroll waves using absorptive transillumination imaging JOURNAL OF BIOMEDICAL OPTICS 12 -, 2007
DOI:10.1117/1.2709661
Wellner M; Bernus O; Mironov SF; Pertsov AM Multiplicative optical tomography of cardiac electrical activity PHYSICS IN MEDICINE AND BIOLOGY 51 4429-4446, 2006
DOI:10.1088/0031-9155/51/18/001
Ten Tusscher KHWJ; Bernus O; Hren R; Panfilov AV Comparison of electrophysiological models for human ventricular cells and tissues PROGRESS IN BIOPHYSICS&MOLECULAR BIOLOGY 90 326-345, 2006
DOI:10.1016/j.pbiomolbio.2005.05.015
Bernus O; Zemlin CW; Matiukas A; Hyatt CJ; Pertsov AM Intra-myocardial cusp waves and their manifestation in optical mapping signals Annual International Conference of the IEEE Engineering in Medicine and Biology - Proceedings 1564-1567, 2006
Khait VD; Bernus O; Mironov SF; Pertsov AM Method for the three-dimensional localization of intramyocardial excitation centers using optical imaging JOURNAL OF BIOMEDICAL OPTICS 11 -, 2006
DOI:10.1117/1.2204030
Pertsov AM; Zemlin CW; Hyatt CJ; Bernus O What can we learn from the optically recorded epicardial action potential? BIOPHYSICAL JOURNAL 91 3959-3960, 2006
DOI:10.1152/biophysj.106.091835
Bernus O; Zemlin CW; Matiukas A; Hyatt CJ; Pertsov AM; IEEE Intra-myocardial cusp waves and their manifestation in optical mapping signals, 2006
Bernus O; Zemlin CW; Zaritsky RM; Mironov SF; Pertsov AM Alternating conduction in the ischaemic border zone as precursor of reentrant arrhythmias: A simulation study EUROPACE 7 S93-S104, 2005
DOI:10.1016/j.eupc.2005.03.018
Wellner M; Mironov SF; Bernus O; Pertsov AM Three-dimensional reconstruction of electrical activity in the heart using optical parallax, 2005
DOI:10.1117/12.589366
Bernus O; Khait VD; Wellner M; Mironov SF; Pertsov AM The forward problem in optical mapping of electrical activity in the heart: Application to various imaging methods, 2005
DOI:10.1117/12.589377
Bernus O; Wellner M; Mironov SF; Pertsov AM Simulation of voltage-sensitive optical signals in three-dimensional slabs of cardiac tissue: application to transillumination and coaxial imaging methods PHYSICS IN MEDICINE AND BIOLOGY 50 215-229, 2005
DOI:10.1088/0031-9155/50/2/003
Bernus O; Wellner M; Pertsov AM Intramural wave propagation in cardiac tissue: Asymptotic solutions and cusp waves PHYSICAL REVIEW E 70 -, 2004
DOI:10.1103/PhysRevE.70.061913
Bernus O; Zemlin CW; Mironov SF; Pertsov AM Conduction alternans in the ischemic border zone as a precursor of reentrant arrhythmias, 2004
Bernus O; Wellner M; Pertsov AM Intramural wave propagation in cardiac tissue: Asymptotic solutions and cusp waves Physical Review E - Statistical, Nonlinear, and Soft Matter Physics 70 061913-1-061913-7, 2004
Bernus O; Verschelde H; Panfilov AV Reentry in an anatomical model of the human ventricles INTERNATIONAL JOURNAL OF BIFURCATION AND CHAOS 13 3693-3702, 2003
DOI:10.1142/S021812740300896X
Bernus O; Verschelde H; Panfilov AV; IEEE The role of Ca2+-channel blockers in the transition from ventricular fibrillation to ventricular tachycardia in an anatomical model of the human ventricles: a simulation study, 2003
Bernus O; Verschelde H; Panfilov AV Spiral wave stability in cardiac tissue with biphasic restitution PHYSICAL REVIEW E 68 -, 2003
DOI:10.1103/PhysRevE.68.021917
Bernus O; Verschelde H; Panfilov AV Spiral wave stability in cardiac tissue with biphasic restitution Physical Review E - Statistical, Nonlinear, and Soft Matter Physics 68 021917/1-021917/6, 2003
Bernus O; Wilders R; Zemlin CW; Verschelde H; Panfilov AV A computationally efficient electrophysiological model of human ventricular cells AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY 282 H2296-H2308, 2002
DOI:10.1152/ajpheart.00731.2001
Bernus O; Verschelde H; Panfilov AV Modified ionic models of cardiac tissue for efficient large scale computations PHYSICS IN MEDICINE AND BIOLOGY 47 1947-1959, 2002
DOI:10.1088/0031-9155/47/11/308
Bernus O; Van Eyck B; Verschelde H; Panfilov AV Transition from ventricular fibrillation to ventricular tachycardia: a simulation study on the role of Ca2+-channel blockers in human ventricular tissue PHYSICS IN MEDICINE AND BIOLOGY 47 4167-4179, 2002
DOI:10.1088/0031-9155/47/23/304
