A global display of the heart vector (spherocardiogram). Applicability of vector-and polarcardiographic infarct criteria.
The spatial loop of the heart vector can be projected on the Aitoff projection of the globe. The complete information that is contained in the orthogonal leads in displayed on a single graph when the vector magnitudes are indicated by the diameter of circles drawn around the vector projection in short time intervals (spherocardiogram). Diagnostic vector- and polarcardiographic criteria were applied to the spherocardiograms of 68 survivors of inferior myocardial infarction and 30 healthy men. Sensitivity increased from 65% (standard 12-lead ECG) to 87% (VCG criteria) (P less than 0.001) to 94% (VCG and PCG criteria combined), with no false-positive diagnoses. The spherocardiogram can be obtained by use of an "intelligent plotter." In contrast to the vectorcardiogram (VCG) and the polarcardiogram (PCG), it permits the direct visual study of the spatial direction and the spatial magnitude of the heart vector and of their sequential changes during the heart cycle.