Ranking the Influence of Tissue Conductivities on Forward-Calculated ECGs

Abstract

This paper examined the effects that different tissue conductivities had on forward-calculated ECGs. To this end, we ranked the influence of tissues by performing repetitive forward calculations while varying the respective tissue conductivity. The torso model included all major anatomical structures like blood, lungs, fat, anisotropic skeletal muscle, intestine, liver, kidneys, bone, cartilage, and spleen. Cardiac electrical sources were derived from realistic atrial and ventricular simulations. The conductivity rankings were based on one of two methods: First, we considered fixed percental conductivity changes to probe the sensitivity of the ECG regarding conductivity alterations. Second, we set conductivities to the reported minimum and maximum values to evaluate the effects of the existing conductivity uncertainties. The amplitudes of both atrial and ventricular ECGs were most sensitive for blood, skeletal muscle conductivity and anisotropy as well as for heart, fat, and lungs. If signal morphology was considered, fat was more important whereas skeletal muscle was less important. When comparing atria and ventricles, the lungs had a larger effect on the atria yet the heart conductivity had a stronger impact on the ventricles. The effects of conductivity uncertainties were significant. Future studies dealing with electrocardiographic simulations should consider these effects.

Influence of Torso Model Complexity on the Noninvasive Localization of Ectopic Ventricular Activity

“…Impact of the complexity of the patient-specific geometry (organs and their conductivities in the volume conductor model) on surface potentials was studied by Doessel [21] and Zemzemi [22]. Global study of the influence of the torso inhomogeneities on atrial and ventricular ECG signals was performed in [21].…”

“…Global study of the influence of the torso inhomogeneities on atrial and ventricular ECG signals was performed in [21]. Realistic forward simulations showed that the conductivity of blood in the main vessels had high impact on the atrial signals.…”

Forward Problem in Electrocardiogram: A Review of Certain Approaches

“…These are also referred to as inhomogeneties. The various tissues, fluids, and structures are known to vary with respect to their conductivities (1). Hence the mentioned torso model includes all major anatomical structures like blood, lungs, fat, anisotropic skeletal muscle intestine, liver, kidneys, bone, cartilage and spleen.…”

euHeart: personalized and integrated cardiac care using patient-specific cardiovascular modelling

“…Endocardial data acquisition is available for one of those patients as a way to evaluate the accuracy of activation time reconstruction. The analysis of those datasets requires performing several image-and signal-processing steps [31,39]. These include the wholeheart MRI segmentation for the endocardium of the ventricles and atria and epicardium of the left ventricles (LVs).…”