A system includes two or more pairs of electrodes and a processor. The electrodes are disposed over a distal end of a catheter for insertion into a heart of a patient. The electrodes in each pair are parallel with one another, and the pairs are not parallel with one another. The processor is configured to receive electrophysiological (EP) signals acquired by the pairs of electrodes, and, based on a timing of the received EP signals, calculate a local direction at which the received EP signals propagate in the heart.