Body surface potential maps

Liebman E, Thomas W, Rudy Y, Plonsey R (1981) Electrocardiographic body surface potential maps of the QRS of normal children. J Electrocardiology 14 249-260... 

The major clinical use of ECG analysis, in all its forms, has been restricted to diagnosis alone. The efforts of many researchers, as well as that of industry, has been devoted quite successfully to the interpretation of the morphology of a single beat from a single (or multiple) lead ECG, or of a single frame of a body surface potential map. An impressive effort has also been invested in the analysis... 

The generation of surface ECG or body surface potential maps directly or through transfer coefficients from the epicardium to the body surface (Hersh et al, 1978 Barr et al. 1977 Spach et al., 1975a 1975b 1977). 

Another problem which has to be solved in order to achieve the desired integrated view of the global heart is the transfer function from the source potentials of the heart to the body surface potentials which are measured either by routine ECG, vector cardiography, or the new techniques of surface potential mapping (Liebman et al, 1981 Hinsen et al, 1981). The forward problem of transforming known source potentials to surface potential maps, based on electri-... 

Figure 9. Examples of regional cardiac events that are reflected in the body surface potential distribution. The surface potential distributions shown in the figure were obtained with our 180-electrode mapping system. Potential levels are displayed as different colors (the color scale is given in microvolts). Each map is divided into four segments, from left to right right chest, left chest, left back, and right back. The time from the beginning of the ORS (in ms), and the maximum and minimum potential values (in microvolts) are displayed below each map.

A very important consequence of potential theory is that in prineiple, epicardial potentials can be recovered from body surface data. Based on this capability, there is hope that epicardial data may be available noninvasively through computations based on body surface potentials (obtained by mapping techniques) and body geometry. The availability of the potential distribution over the entire torso (nearly a closed surface) permits such inverse transformation to be investigated. 

King TD, Barr RC, Herman-Giddens GS, Boaz DE, Spach MS (1972) Isopotential body surface maps and their relationship to atrial potentials in the dog. Circ Res 20 393-405 Martin RO, Pilkington TC (1972) Unconstrained inverse electrocardiography Epicardial potentials. IEEE Trans Biomed Eng 19 276-285... 

Clementi (1985) described ab initio computational chemistry as a global approach to simulations of complex chemical systems, derived directly from theory without recourse to empirical parametrizations. The intent is to break the computation into steps quantum mechanical computations for the elements of the system, construction of two-body potentials for the interactions between them, statistical mechanical simulations using the above potentials, and, finally, the treatment of higher levels of chemical complexity (e.g., dissipative behavior). This program has been followed for analysis of the hydration of DNA. Early work by Clementi et al. (1977) established intermolecular potentials for the interaction of lysozyme with water, given as maps of the energy of interaction of solvent water with the lysozyme surface. 

---