The QRS electrocardiogram, epicardiogram, vectorcardiogram and ventricular excitation of swine

¹ Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine, Ohio State University, Columbus, Ohio

The ventricular activation process of normal pigs as estimated qualitatively from body surface potentials and epicardial electrograms is similar to that accurately described for the dog. Ventricular excitation may be divided sequentially into three components: interventricular septal from left to right, ventricular free-wall from endocardium to epicardium, and septal and ventricular basilar in an apico-basilar direction. The differences between the body surface potentials recorded from the dog and from the pig lies in the greater dorsal magnitude of the terminal basilar forces in the pig.