Spatial Vectorcardiograms in Normal Dogs

Abstract

The spatial vectoreardiogram was recorded on 34 normal mongrel dogs employing the equilateral tetrahedral reference system. The QRS sÊ-loop was long, narrow, and elliptical, and oriented slightly to the left, ventrad and caudad, the majority of the maximal vectors lying in the fifth sextant of the triaxial reference system in both the anterior and left sagittal plane projections. The trace was inscribed in a counterclockwise direction in the frontal and left sagittal plane projections for most of the dogs. The P and T sÊ-loops were essentially of the same configuration and had the same spatial orientation as the QRS sÊ-loops, except that T sÊ-loops were often oriented in the second sextant of the triaxial reference system in both the frontal and left sagittal plane projections.