Computer analysis of the spatial angular parameters of the canine QRSsE loop from necropsy-verified normal dogs

Vectorcardiograms were recorded by the canine modification of the axial lead system of McFee and Parungao from 38 necropsy-verified normal dogs placed in the recommended position of right lateral recumbency. A digital computer program was used to identify and analyze the spatial characteristics of the QRSsE loop. In order to define the QRSsE loop in more complete terms, a total of 27 angular parameters were evaluated. Time to specified parameters and angular values at specified times were assessed. The smallest angular range for a frontal plane vector was 15.7 degrees which occurred with the maximum leftward vector. In the sagittal plane the most narrow range was 29.8 degrees found with the half-area vector. The most narrow angular range in the transverse plane was 29.7 degrees with the maximum leftward vector. Other characteristics of the normal dog were found, such as the simultaneous occurrence of the following vectors: the peak spatial magnitude vector; frontal plane maximum vector; maximum leftward vector; maximum caudal vector; sagittal plane half-area vector; and transverse plane maximum vector. Also occurring together, but at a different time, were the sagittal plane maximum vector and the transverse plane half-area vector.