Cardiogoniometry is a new vectorcardiographic method. The vector-loops are constructed from three orthogonal ECG leads and registered on-line by a microprocessor. The angle between the maximal QRS and T vectors, as well as the spatial orientation of these vectors are very constant in healthy individuals. Deviations of these vectors and angles are sensitive indicators for changes in repolarization occurring, for instance, during coronary insufficiency. The changes in these variables were evaluated in 50 patients with suspected coronary artery disease and correlated with angiographic findings. Cardiogoniometry showed a sensitivity of 79% and a specificity of 82%, which is comparable to exercise testing. In contrast to the latter cardiogoniometry can be performed at rest, is free of risk, and therefore also suitable for elderly patients.