Fig. 1

Depiction of the subvalvular lesion through a schematic drawing, pathology image, and echocardiography. a An illustration of a healthy (top) and SAS affected (bottom) canine heart. The arrow points to the aortic valve (top) and subvalvular ridge (bottom). This image was reprinted (with permission) from the Ontiveros et al. manuscript [33]. b A gross pathology image of a heart affected with SAS with the subvalvular ridge/ring denoted by the arrow. c 2D, color (upper image) and spectral (lower image) Doppler echocardiogram images of a dog with severe SAS. Note the turbulent blood flow and high aortic flow velocity consistent with severe subvalvular aortic stenosis. The subvalvular lesion is denoted by the white arrow in the top left panel of this image. The left ventricle (LV), aorta (Ao) and left atrium (LA) are noted