Aimed Electrocardiography with Simple Bipolar Leads

Abstract

All currently employed ECG and VCG leads vectorially record added contributions from all cardiac regions. Aimed leads, if feasible, would yield information cancelled during addition. Three artificial dipoles (µ 1 , µ 2 , µ 3 ) are placed within a torso model in the approximate right ventricular free wall, posterobasal wall of left ventricle, and inferior cardiac surface, respectively. Dipoles are excited in turn and torso surface potential fields are mapped for each dipole. A bipolar lead connecting any pair of points on the same equipotential of the field produced by µ 1 does not show a deflection when µ 1 is excited, but responds to µ 2 and µ 3 . If this lead is now so placed that its two electrodes, while remaining on the µ 1 equipotential, are on the same equipotential of the µ 2 field as well, then it will respond to µ 3 alone; it is aimed at the latter. Superimposing the three field maps and searching for those equipotential lines of one map which cross the same equipotential line of another map twice, provides a large number of suitable leads, each aimed at one of the three dipoles. Five leads are described and tested in detail.