EECG imaging - Combination of 3D Echo- and inverse ElectroCardioGraphy

In combination with morphological imaging modalities (e.g., magnetic resonance imaging (MRI) or Computed Tomography (CT)) the noninvasive imaging of electrical function in the human heart has attained increasing importance because of the availability of electrocardiographic (ECG) and magnetocardiographic (MCG) mapping systems and recently developed inverse algorithms. Some basic mathematical and numerical methods for source imaging have been developed by our working group during the last years. Recently, two invasive catheter mapping systems (CARTOTM (Biosense Inc., Johnson&Johnson), EnSiteTM (Endocardial Solutions Inc., Medtronic Inc.)) have been introduced into clinical electrophysiology. The inverse methods developed in Graz, which will be further developed and validated in this project, allow the noninvasive determination of the activation and repolarization time map on the entire surface of the heart from ECG and MCG mapping data. From the cardiologists` point of view this method will become an attractive alternative to the invasive catheter mapping methods and will help to reduce the patients` risk due to a significant shortening of the invasive procedure time. About the world big efforts have been done in order to develop methods for functional cardiac electrical source imaging. But so far, the technical and clinical breakthrough of this new imaging method has not been achieved. Technical research and development will be focussed on the modeling of 3D anatomical data (ultrasound, MRI), on the further development of the source imaging algorithms, on atrial anatomical modeling (geometrical anisotropy), on a method describing noninvasively spatio-temporal organization of atrial fibrillation and on a novel approach optimizing the position and orientation of the (surface) heart model in the inverse problem. The combination of ECG mapping with 3D cardiac ultrasound will be one of the key research areas. Due to this novel combination an online (catheter laboratory) and single beat inverse approach will be feasible. Source imaging within the atrium will be another research topic. Very important clinical validation studies will be carried out in collaboration with the University Hospital Innsbruck, University Clinic for Internal Medicine, Department of Cardiology (60 patients, catheter measurements, (128/64-channel) ECG map, MRI (torso, (cine) cardiac), 3D ultrasound (cine); sinus rhythm, ectopy, pre-excitation fibrillation, flutter, tachycardia). Source imaging from MCG data (with simultaneously recorded multichannel ECG maps) will be investigated together with the University of California San Francisco and with the Helsinki University Central Hospital (Helsinki University of Technology). Influence of the proposed work on the development of the field The research performed in this project will have an essential impact on the development of electrocardiography, both in basic science and in clinical application. Based on the research in this project the main goal will be the further development and establishment of inverse electrocardiography. The investigated inverse approach, in particular the imaging of the activation and repolarization time map on the surface of the heart (ventricle, atrium), will be further developed and established as the state-of-the art technique for cardiac electrical source imaging. In combination with ultrasound, MRI and CT this inverse approach allows for the first time to determine noninvasively activation and repolarization time maps, so far only obtained with invasive catheter mapping systems (e.g., with CARTO TM ). In particular, in this project we will focus on 3D cardiac ultrasound for anatomical imaging. Herewith, in combining echo- and electrocardiography (EECG) the proposed inverse approach enables the extension of existing 3D cardiac ultrasound techniques (anatomical and Doppler imaging) by imaging of cardiac electrical function. It can be expected that this will have a dramatic impact on the clinical application of ultrasound in the near future. Beside, the same inverse approach can be applied in combination with MRI or CT data. The huge impact on clinical electrophysiology will be to have then available a new noninvasive tool for imaging premature and extrasystolic cardiac beats, tachycardia, flutter, fibrillation, and infarction.

In combination with morphological imaging modalities (e.g., magnetic resonance imaging (MRI) or Computed Tomography (CT)) the noninvasive imaging of electrical function in the human heart has attained increasing importance because of the availability of electrocardiographic (ECG) and magnetocardiographic (MCG) mapping systems and recently developed inverse algorithms. Some basic mathematical and numerical methods for source imaging have been developed by our working group during the last years. Recently, two invasive catheter mapping systems (CARTOTM (Biosense Inc., Johnson&Johnson), EnSiteTM (Endocardial Solutions Inc., Medtronic Inc.) have been introduced into clinical electrophysiology. The inverse methods developed in Graz, which will be further developed and validated in this project, allow the noninvasive determination of the activation and repolarization time map on the entire surface of the heart from ECG and MCG mapping data. From the cardiologists` point of view this method will become an attractive alternative to the invasive catheter mapping methods and will help to reduce the patients` risk due to a significant shortening of the invasive procedure time. About the world big efforts have been done in order to develop methods for functional cardiac electrical source imaging. But so far, the technical and clinical breakthrough of this new imaging method has not been achieved. Technical research and development will be focussed on the modeling of 3D anatomical data (ultrasound, MRI), on the further development of the source imaging algorithms, on atrial anatomical modeling (geometrical anisotropy), on a method describing noninvasively spatio-temporal organization of atrial fibrillation and on a novel approach optimizing the position and orientation of the (surface) heart model in the inverse problem. The combination of ECG mapping with 3D cardiac ultrasound will be one of the key research areas. Due to this novel combination an online (catheter laboratory) and single beat inverse approach will be feasible. Source imaging within the atrium will be another research topic. Very important clinical validation studies will be carried out in collaboration with the University Hospital Innsbruck, University Clinic for Internal Medicine, Department of Cardiology (60 patients, catheter measurements, (128/64-channel) ECG map, MRI (torso, (cine) cardiac), 3D ultrasound (cine); sinus rhythm, ectopy, pre-excitation fibrillation, flutter, tachycardia). Source imaging from MCG data (with simultaneously recorded multichannel ECG maps) will be investigated together with the University of California San Francisco and with the Helsinki University Central Hospital (Helsinki University of Technology). Influence of the proposed work on the development of the field The research performed in this project will have an essential impact on the development of electrocardiography, both in basic science and in clinical application. Based on the research in this project the main goal will be the further development and establishment of inverse electrocardiography. The investigated inverse approach, in particular the imaging of the activation and repolarization time map on the surface of the heart (ventricle, atrium), will be further developed and established as the state-of-the art technique for cardiac electrical source imaging. In combination with ultrasound, MRI and CT this inverse approach allows for the first time to determine noninvasively activation and repolarization time maps, so far only obtained with invasive catheter mapping systems (e.g., with CARTO TM ). In particular, in this project we will focus on 3D cardiac ultrasound for anatomical imaging. Herewith, in combining echo- and electrocardiography (EECG) the proposed inverse approach enables the extension of existing 3D cardiac ultrasound techniques (anatomical and Doppler imaging) by imaging of cardiac electrical function. It can be expected that this will have a dramatic impact on the clinical application of ultrasound in the near future. Beside, the same inverse approach can be applied in combination with MRI or CT data. The huge impact on clinical electrophysiology will be to have then available a new noninvasive tool for imaging premature and extrasystolic cardiac beats, tachycardia, flutter, fibrillation, and infarction.