Two approaches to the analysis of spatial electrocardiographic vectors are currently being used: construction from the conventional ECG leads, and measurements from oscilloscopic recordings of spatial loops. There are several fundamental differences between the approaches, and there is noa prioricertainty that equivalent or even similar phenomena are being investigated. This study presents a statistical comparison between mean spatial vectors, constructed from the conventional ECG, and instantaneous maximum spatial vectors, determined with the stereovector electro-cardiographic technic.