Maximal spatial ST vector of S-T segment elevation in the right praecordial leads on electrocardiogram due to acute pericarditis.

Three patients with acute pericarditis with S-T segment elevation in the right praecordial leads were studied by vectorcardiography. The vectorcardiographic findings suggested that, in acute pericarditis, the maximal spatial ST vector pointed to the left-anterior-inferior direction. The S-T segment elevations in the right praecordial leads in these patients were due to the large magnitude of the maximal spatial ST vector. Its magnitude indirectly caused S-T segment elevation in the right praecordial leads adjacent to it during the acute stage of pericarditis.