NORMAL LIMITS OF THE DERIVED VECTORCARDIOGRAM IN CAUCASIANS

The derived vectorcardiogram (dVCG) can be obtained from three orthogo nal leads X, Y, Z, which are synthesized from the conventional 12-lead ECG by one of a number of mathematical techniques. The application of the dVCG in routine cardiological practice has the advantage of not r equiring extra recording electrodes other than those used for the conv entional 12 electrocardiographic leads, and offers the simultaneous av ailability of additional dVCG diagnostic information. In this study, t he dVCGs were obtained using the inverse Dower method from 1555 appare ntly healthy Caucasian individuals (884 men and 671 women) and were an alysed to determine the age and sex dependent normal ranges of vector measurements in a Caucasian population. The vectorcardiographic parame ters measured included the directions of inscription of the QRS vector loops, the magnitude of initial 20 and 30 ms QRS vectors and the dire ction of the initial 20 ms QRS vector. The maximal spatial QRS vector magnitude, as well as the maximal QRS and T vector magnitudes in the f rontal, horizontal, and right sagittal planes, were observed to decrea se significantly with advancing age in both sexes (P<0.001) and were s ignificantly larger in men in all age groups (P<0.001). The observatio ns from the current study illustrate the significant age and sex depen dent differences in the normal ranges of dVCG parameters. These are of potential importance for diagnostic applications.