Outflow tract obstructions are congenital cardiac defects that include aortic stenosis Aortic Stenosis in Animals Aortic stenosis, typically caused by a ridge or ring of fibrotic tissue in the subaortic region (subaortic stenosis), is a common congenital defect of large breed dogs. The condition is typically... read more , pulmonic stenosis Pulmonic Stenosis in Animals Pulmonic stenosis is a common congenital defect of dogs, and it most commonly involves fusion or dysplasia of the pulmonic valve leaflets (valvar or valvular). This condition affects a variety... read more , and coarctation of the aorta Coarctation of the Aorta in Animals Coarctation of the aorta is a rare condition of dogs and cats that involves narrowing of the aorta distal to the subclavian artery, typically in the area of the ductus arteriosus. Similar to... read more . All involve obstruction to either right or left ventricular outflow. Defects such as double chamber right ventricle, branch pulmonary artery stenosis, and cor triatriatum also create obstruction to normal blood flow but are not located within the right ventricular or left ventricular outflow tracts.