The aim of this contribution was to review the possibilities of presentation of orthogonal ECG signals and to evaluate the progress in computerized electrocardiography achieved in Czechoslovakia. The information about the cardiac electric field in orthogonal electrocardiography is defined and consequently displayed as a fixed single dipole (vector). The spatial trajectory of vector end-point (spatial vectorcardiographic loop) can be presented in different ways — as orthogonal electrocardiogram, polarcardiogram, planar vectorcardiogram and decartogram, respectively. The advantages of particular methods of presentation, as well as their limitations are discussed. Computer-assisted electrocardiography was introduced in Czechoslovakia in 1974. The original AVA program has been further developed in the Research Institute of Medical Informatics (formerly Research Institute of Medical Bionics). The currently developed system CardioSys allows the utilization of all the possibilities of orthogonal ECG and vectorcardiographic presentation for clinical and epidemiological cardiology as well as for the research.