[Diagnostic significance of the vectorcardiogram spatial indices in combined atrial dilatation].

Eighty-two apparently normal subjects and 90 patients with combined atrial dilatation were investigated, using automated amplified-image atrial VCG reproduction with an output of spatial characteristics of the Macfee-Parungao P loop, a method developed at the All-Union Center for Cardiologic Research (USSR Academy of Medical Sciences). Area enclosed by spatial P loop (SPxyz greater than or equal to 0.017 mV2), mean vector size (MPxyz greater than or equal to 120.6 microV) and P loop duration (tPxyz greater than or equal to 0.116 sec) showed the highest diagnostic value. The use of these integral characteristics of the spatial P loop improved identification of two dilated atria, bringing the detection rate to 92%, as compared to 53.3% obtainable with ECG from 12 standard and orthogonal leads.