[The current clinical importance of corrected orthogonal derivations]

According to the theorectical basic conception corrected orthogonal derivations restrict themselves to the selective establishment of the dipol proportion of the cardio-electric field of the body surface. In contrast to this the 12 conventional derivations give a more comprehensive information which in the precordial region also includes non-dipolar field proportions. There is not infrequently the requirement of supplementing this conventional routine programme with the help of further derivations, since also by partly redundant informations the certainty of diagnostic decisions may be increased and circumscribed alterations of the field may become comprehensible. According to recent knowledge the offer of informations which smaller for the routine form of the ECG-evaluation may be extensively redeemed by the calculation of vectorial sizes, which presumes the machine evaluation of the ECG. Also the most trained imaginative faculty is not able to estimate more exactly the course of the vector loops from the 3 corrected derivations. As long as the economical and technical problems including the evaluation programmes for a machine processing of the ECG are not solved, the corrected derivations are of no clinical importance. Their use is restricted to only few centres interested in science.