Assessment of the equivalent dipole layer source model in the reconstruction of cardiac activation times on the basis of BSPMs produced by an anisotropic model of the heart

Contains fulltext : 191955.pdf (Publisher’s version ) (Open Access

Modeling the His-Purkinje Effect in Non-invasive Estimation of Endocardial and Epicardial Ventricular Activation

Inverse electrocardiography (iECG) estimates epi- and endocardial electrical activity from body surface potentials maps (BSPM). In individuals at risk for cardiomyopathy, non-invasive estimation of normal ventricular activation may provide valuable information to aid risk stratification to prevent sudden cardiac death. However, multiple simultaneous activation wavefronts initiated by the His-Purkinje system, severely complicate iECG. To improve the estimation of normal ventricular activation, the iECG method should accurately mimic the effect of the His-Purkinje system, which is not taken into account in the previously published multi-focal iECG. Therefore, we introduce the novel multi-wave iECG method and report on its performance. Multi-wave iECG and multi-focal iECG were tested in four patients undergoing invasive electro-anatomical mapping during normal ventricular activation. In each subject, 67-electrode BSPM were recorded and used as input for both iECG methods. The iECG and invasive local activation timing (LAT) maps were compared. Median epicardial inter-map correlation coefficient (CC) between invasive LAT maps and estimated multi-wave iECG versus multi-focal iECG was 0.61 versus 0.31. Endocardial inter-map CC was 0.54 respectively 0.22. Modeling the His-Purkinje system resulted in a physiologically realistic and robust non-invasive estimation of normal ventricular activation, which might enable the early detection of cardiac disease during normal sinus rhythm

Realistic mean field forward predictions for the integration of co-registered EEG/fMRI.

Contains fulltext : 81743.pdf (publisher's version ) (Open Access

The potential distribution generated by the fetal heart at the maternal abdomen

Peer Reviewe

Application of the fastest route algorithm in the interactive simulation of the effect of local ischemia on the ECG

A method is described to determine the effect on the ECG of a reduced propagation velocity within an ischemic zone. The method was designed to change the activation sequence throughout the ventricles interactively, i.e. with a response time in the order of a second. The timing of ventricular ischemic activation was computed by using the fastest route algorithm, based on locally reduced values of the propagation velocities derived from a standard, normal activation sequence. The effect of these local reductions of the velocities on the total activation sequence, as well as the changes in the electrocardiogram that these produce, are presented

Improving the Accuracy of Forward Computations: Different Methods to Implement the Propagation of the Depolarization Wave Front

Abstract This study addresses the problem of discontinuities in the body surface potentials (BSPs

Model-based inferences for clinical applications of the ECG

Doctor Macchi reported on the progress of an animal model study of electric propagation initiated by electric stimuli. Doctor Oostendorp first gave an introduction to the inverse problem of cardiac activation time mapping (ATM), the determination of the depolarization times at the myocardial surface as computed from the equivalent double layer (EDL) source model, and a biophysical model of the volume conductor involved: the passive conductive tissues inside the thorax. Doctor van Oosterom presented some results from an ongoing study aimed at extracting more information about the atrial electric activity from potentials observed on the body surface: the ECG. Doctor Zabel discussed the potential of using a standard 12-lead ECG device for estimating body surface potential maps