The canine J wave

Abstract

The J wave is a deflection immediately following the QRS complex of the surface ECG. The J wave has been observed in humans under physiological and pathophysiological conditions. We describe in this paper the ratio of incidence of this phenomenon in healthy dogs and dogs with pathological disease and the effect of exercise on its size and shape. At rest, a J wave was observed at the R-ST junction of the ECG in 11 of 34 adult dogs, usually in leads I, II, III, aVR, and aVF and left lateral precordial leads. After a submaximal exercise test there were no variations in the shape or the size of the J wave.