Description

The heart is an electromechanical pump: for the myocardial cells to contract, they need to be electrically activated. In the healthy heart, natural pacemakers in the sino-atrial node generate propagating action potentials producing a depolarization wave that eventually covers the whole myocardium. Because the conduction properties of the diseased heart are different from normal tissue, the timings and patterns of this wave can be use to localize and characterize diseased regions. However, as of today, there is no non-invasive method available clinically to track this wave.

Electromechanical Wave Imaging (EWI) is an ultrasound-based imaging method that can map the electromechanical activity in all four heart chambers at very high spatial and temporal resolution, non-invasively and with real-time feedback. At the tissue level, the depolarization of myocardial regions triggers the electromechanical activation, i.e., the first time, at which the muscle transitions from a relaxation to a contraction state. Spatially, this electromechanical activation forms the EW front that follows the propagation pattern of the electrical activation sequence.

EWI could be used to assist in the diagnosis and treatment planning, monitoring and follow-up of patients with arrhythmias or undergoing pacing therapies in a non-invasive, low-cost, and real-time manner.

Results

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	EWI isochrones of a normal sinus rhythm obtained noninvasively in a normal human subject These isochrones depict an electromechanical activation sequence and are in excellent agreement with the transmural electrical activation sequence obtained in ex vivo human heart in prior litterature (for example, Durrer et al. 1970). This sequence cannot be measured in humans with any currently used clinical method. Source: Konofagou & Provost (2012) Posted on Thursday April 26, 2012 at 8:26 AM
	EWI performed at 2000 fps using a virtual-source sequence in a conscious, closed-chest canine during sinus rhythm The normal transmural electromechanical activation sequence can be obtained non-invasively. Here, activation originates in the right atrium, propagates in the left atrium, and emerges from multiple origins in the ventricles. Source: Provost et al. (2011) Posted on Saturday November 5, 2011 at 4:19 PM
	EWI cine-loop frames The images depict the propagation of the electromechanical wave (in red) in a paced canine heart in vivo. Source: Provost et al. (2011) Posted on Tuesday May 17, 2011 at 2:50 PM
	Validation of EWI using an in silico-in vivo framework The EWI isochrones were reproduced using anatomically-realistic electromechanical simulations developed by the group of Dr. Natalia Trayanova at Johns Hopkins University. This framework allows the validation of the correlation between the electrical and electromechanical activation sequences at every location of the heart, which is not feasible at this time using only experimental methods. Source: Provost et al. (2011) Posted on Thursday May 12, 2011 at 12:20 PM
	Ischemic region sizes detected using EWI for different coronary flow decrements The colors denote the amplitude of the strains in the heart (blue for negative strains, red for positive strains). Source: Provost et al. (2010) Posted on Friday March 12, 2010 at 3:58 PM

To obtain the citations for all of the publications related to this project, click here to download the complete list (in BibTeX format).

Journal Articles

	Electromechanical wave imaging for noninvasive mapping of the 3D electrical activation sequence in canines and humans in vivo Elisa E. Konofagou, Jean Provost Journal of Biomechanics, Volume 45, Number 5, Pages 856-864, April 2012 Digital Object Identifier: 10.1016/j.jbiomech.2011.11.027 Download Full Text (PDF) | Download Citation (BibTeX)
	Single-heartbeat electromechanical wave imaging with optimal strain estimation using temporally-unequispaced acquisition sequences Jean Provost, Stéphane Thiébaut, Jianwen Luo, Elisa E. Konofagou Physics in Medicine and Biology, Volume 57, Pages 1095-1112, 2012 Digital Object Identifier: 10.1088/0031-9155/57/4/1095 Download Full Text (PDF) | Download Citation (BibTeX)
	Elevated strain and structural disarray occur at the right ventricular apex Venkatesh Hariharan, Jean Provost, S. Shah, Elisa E. Konofagou, Hayden Huang Cardiovascular Engineering and Technology, Volume 3, Number 1, Pages 52-61, 2012 Digital Object Identifier: 10.1007/s13239-011-0081-3 Download Full Text (PDF) | Download Citation (BibTeX)
	Electromechanical wave imaging for arrhythmias Jean Provost, Vu Thanh-Hieu Nguyen, Diégo Legrand, Stanley J. Okrasinski, Alexandre Costet, Alok Gambhir, Hasan Garan, Elisa E. Konofagou Physics in Medicine and Biology, Volume 56, Number 22, Pages 1-11, November 2011 Digital Object Identifier: 10.1088/0031-9155/56/22/F01 Download Full Text (PDF) | Download Citation (BibTeX)
	Mapping of cardiac electrical activation with electromechanical wave imaging: an in silico-in vivo reciprocity study Jean Provost, Viatcheslav Gurev, Natalia Trayanova, Elisa E. Konofagou Heart Rhythm: The Official Journal of the Heart Rhythm Society, Volume 8, Number 5, Pages 752-759, May 2011 Digital Object Identifier: 10.1016/j.hrthm.2010.12.034 Download Full Text (PDF) | Download Citation (BibTeX)
	Imaging the electromechanical activity of the heart in vivo Jean Provost, Wei-Ning Lee, Kana Fujikura, Elisa E. Konofagou Proceedings of the National Academy of Sciences of the USA, Volume 108, Number 21, Pages 8565-8570, May 2011 Digital Object Identifier: 10.1073/pnas.1011688108 Download Full Text (PDF) | Download Citation (BibTeX)
	Electromechanical wave imaging of normal and ischemic hearts in vivo Jean Provost, Wei-Ning Lee, Kana Fujikura, Elisa E. Konofagou IEEE Transactions on Medical Imaging, Volume 29, Number 3, Pages 625-635, March 2010 Digital Object Identifier: 10.1109/TMI.2009.2030186 Download Full Text (PDF) | Download Citation (BibTeX)
	Non-invasive electromechanical wave imaging and conduction-relevant velocity estimation in vivo Elisa E. Konofagou, Jianwen Luo, Deepak Saluja, Daniel O. Cervantes, James Coromilas, Kana Fujikura Ultrasonics, Volume 50, Number 2, Pages 208-215, February 2010 Digital Object Identifier: 10.1016/j.ultras.2009.09.026 Download Full Text (PDF) | Download Citation (BibTeX)
	A composite high-frame-rate system for clinical cardiovascular imaging Shougang Wang, Wei-Ning Lee, Jean Provost, Jianwen Luo, Elisa E. Konofagou IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, Volume 55, Number 10, Pages 2221-2233, October 2008 Digital Object Identifier: 10.1109/TUFFC.921 Download Full Text (PDF) | Download Citation (BibTeX)

Conference Papers and Presentations

	Electromechanical Wave Imaging of atrial fibrillation in humans: a feasibility study. Alexandre Costet, Jonathan T. Lu, Elisa E. Konofagou IEEE International Ultrasonics Symposium (Prague, Czech Republic), July 21 to 25, 2013 Download Citation (BibTeX)
	High framerate lateral strain estimation using virtual beam focusing in canine and human hearts in vivo Ethan A. Bunting, Jean Provost, Elisa E. Konofagou American Institute of Ultrasound in Medicine Annual Convention (New York, NY, USA), April 6 to 10, 2013 Download Citation (BibTeX)
	Single-heartbeat electromechanical wave imaging in humans during arrhythmia Jean Provost, Alok Gambhir, Hasan Garan, Elisa E. Konofagou IEEE International Ultrasonics Symposium (Dresden, Germany), October 7 to 10, 2012 Download Citation (BibTeX)
	Electromechanical wave imaging of stem cell and viral cardiac pacing in conscious dogs in vivo Alexandre Costet, Jean Provost, Alok Gambhir, Gerard J. J. Boink, Peter Danilo Jr., Michael R. Rosen, Elisa E. Konofagou IEEE International Ultrasonics Symposium (Dresden, Germany), October 7 to 10, 2012 Download Citation (BibTeX)
	Electromechanical wave imaging of stem cell and viral cardiac pacing in conscious dogs in vivo Alexandre Costet, Jean Provost, Alok Gambhir, Yevgeniy Bobkov, Gerard J. J. Boink, Peter Danilo Jr., Michael R. Rosen, Elisa E. Konofagou 11th International Tissue Elasticity Conference (Deauville, France), October 2 to 5, 2012 Download Citation (BibTeX)
	Electromechanical wave imaging of canine and human pathological hearts in vivo Jean Provost, Alok Gambhir, Alexandre Costet, Julien L. Grondin, Stanley J. Okrasinski, Elisa E. Konofagou 11th International Tissue Elasticity Conference (Deauville, France), October 2 to 5, 2012 Download Citation (BibTeX)
	Single-heartbeat electromechanical wave imaging with optimal strain estimation using temporally-unequispaced acquisition sequences Jean Provost, Stanley J. Okrasinski, Alexandre Costet, Julien L. Grondin, Alok Gambhir, Hasan Garan, Elisa E. Konofagou 37th International Symposium on Ultrasonic Imaging and Tissue Characterization (Arlington, VA, USA), June 11 to 13, 2012 Invited Contribution Download Citation (BibTeX)
	Transthoracic electromechanical wave imaging of stem cell and viral pacing of the canine heart in vivo Alexandre Costet, Jean Provost, Alok Gambhir, Peter Danilo Jr., Elisa E. Konofagou 33rd Heart Rhythm Society Annual Scientific Sessions (Boston, MA, USA), May 9 to 12, 2012 Download Citation (BibTeX)
	Non-invasive electromechanical imaging of atrial supraventricular and ventricular cardiac conduction disorders in canines and humans Jean Provost, Alok Gambhir, Stéphane Thiébaut, Vu Thanh-Hieu Nguyen, J. Vest, Hasan Garan, Elisa E. Konofagou IEEE International Ultrasonics Symposium (Orlando, FL, USA), October 18 to 21, 2011 Download Citation (BibTeX)
	Single-heartbeat electromechanical wave imaging with optimal strain estimation using temporally-unequispaced acquisition sequences Jean Provost, Stéphane Thiébaut, Jianwen Luo, Elisa E. Konofagou 10th International Tissue Elasticity Conference (Arlington, TX, USA), October 12 to 15, 2011 Download Citation (BibTeX)
	Electromechanical wave imaging for noninvasive mapping of the 3D electrical activation sequence in vivo Jean Provost, Wei-Ning Lee, Kana Fujikura, Elisa E. Konofagou American Heart Association Scientific Sessions (Chicago, IL, USA), November 13 to 17, 2010 Download Citation (BibTeX)
	Mapping the electrical activation sequence of the heart using electromechanical wave imaging: a validation study in canines Jean Provost, Wei-Ning Lee, Kana Fujikura, Elisa E. Konofagou 9th International Tissue Elasticity Conference (Snowbird, UT, USA), October 16 to 19, 2010 Download Citation (BibTeX)
	Validation of electromechanical wave imaging for mapping of the regional cardiac electrical activity noninvasively in vivo Jean Provost, Viatcheslav Gurev, Natalia Trayanova, Elisa E. Konofagou IEEE International Ultrasonics Symposium (San Diego, CA, USA), October 11 to 14, 2010 Download Citation (BibTeX)
	A noninvasive direct method for cardiac mapping: electromechanical wave imaging Jean Provost, Stanley J. Okrasinski, Wei-Ning Lee, Kana Fujikura, Elisa E. Konofagou 31st Heart Rhythm Society Annual Scientific Sessions (Denver, CO, USA), May 12 to 15, 2010 Download Citation (BibTeX)
	Electromechanical wave imaging: non-invasive localization and quantification of partial ischemic regions in vivo Jean Provost, Wei-Ning Lee, Kana Fujikura, Elisa E. Konofagou IEEE International Ultrasonics Symposium (Rome, Italy), September 18 to 21, 2009 Download Citation (BibTeX)
	Characterization of wave origins in electromechanical wave imaging Jean Provost, Viatcheslav Gurev, Jianwen Luo, Natalia Trayanova, Elisa E. Konofagou IEEE International Ultrasonics Symposium (Beijing, China), November 2 to 5, 2008 Download Citation (BibTeX)
	Electromechanical wave propagation in the normal and ischemic canine myocardium in vivo Jean Provost, Wei-Ning Lee, Kana Fujikura, Elisa E. Konofagou 7th International Tissue Elasticity Conference (Austin, TX, USA), October 27 to 30, 2008 Download Citation (BibTeX)
	Mapping and characterization of electromechanical wave propagation in the left ventricle in vivo Jean Provost, Jianwen Luo, Elisa E. Konofagou Society for Industrial and Applied Mathematics Conference on the Life Sciences (Montréal, Québec, Canada), August 4 to 7, 2008 Download Citation (BibTeX)
	Noninvasive electromechanical wave imaging and conduction velocity estimation in vivo Elisa E. Konofagou, Jianwen Luo, Deepak Saluja, Kana Fujikura, Daniel O. Cervantes, James Coromilas Proceedings of the IEEE International Ultrasonics Symposium (New York, NY, USA), October 28 to 31, 2007 Download Full Text (PDF) | Download Citation (BibTeX)
	Imaging the electromechanical wave activation of the left ventricle in vivo Elisa E. Konofagou, Jianwen Luo, Kana Fujikura, Daniel O. Cervantes, James Coromilas Proceedings of the IEEE International Ultrasonics Symposium (Vancouver, BC, Canada), October 2 to 5, 2006 Download Full Text (PDF) | Download Citation (BibTeX)
	Electromechanical imaging of the myocardium at normal and pathological states Mathieu Pernot, Elisa E. Konofagou Proceedings of the IEEE International Ultrasonics Symposium (Rotterdam, The Netherlands), September 17 to 20, 2005 Download Full Text (PDF) | Download Citation (BibTeX)

Book Chapter

Evolving concepts in measuring ventricular strain in canine and human hearts: non-invasive imaging Elisa E. Konofagou, Jean Provost Cardiac mechano-electric coupling and arrhythmias (Oxford University Press, Oxford, Oxfordshire, UK), 2011 Download Citation (BibTeX)

Article in the Popular Press

EWI characterizes abnormal heart activity Article in MedicalPhysicsWeb on November 1, 2011 Link: http://medicalphysicsweb.org/cws/article/research/47680 Download Citation (BibTeX)

The researchers involved in this project are listed below.

Principal Investigator

Elisa Konofagou, Ph.D. Email: ek2191 [at] columbia [dot] edu Phone: +1 212 342 0863 Office: PS19-418A View Profile | View Publications

Postdoctoral Research Scientist

Julien Grondin, Ph.D. Email: jlg2216 [at] columbia [dot] edu Phone: +1 212 305 3411 Office: PS19-407 View Profile | View Publications

Ph.D. Students

	Ethan Bunting, B.S. Email: eab2196 [at] columbia [dot] edu Phone: +1 212 305 3411 Office: PS7-442 View Profile | View Publications
	Alexandre Costet, M.Sc. Email: ac3395 [at] columbia [dot] edu Phone: +1 212 305 3411 Office: PS7-442 View Profile | View Publications