Electrocardiogram of the crocodilian heart [1]

Abstract

As part of an investigation of the histology and functional anatomy of the crocodilian heart, electrocardiograms of the heart in intact animals (Nile crocodiles) were recorded. Part of a tracing, using the standard lead, throat to abdomen, is shown in Fig. 1. While the general form of the electrocardiogram is similar to that of the normal human heart (Fig. 2), except that the T-wave is inverted in the crocodile owing to the lead used, significant differences are observed, particularly with reference to the spacing of the several events within the cardiac cycle. © 1951 Nature Publishing Group.