Subvalvular Aortic Stenosis: Learning From Human and Canine Clinical Research

Abstract

Subvalvular aortic stenosis (SAS) is the most common congenital heart disease (CHD) in dogs and is also prevalent in human children. A fibrous ridge below the aortic valve narrows the left ventricular outflow tract (LVOT) and increases blood flow velocity, leading to devastating side effects in diseased patients. Due to the similarities in presentation, anatomy, pathophysiology, cardiac development, genomics, and environment between humans and dogs, canine SAS patients represent a critical translational model of human SAS. Potential adverse outcomes of SAS include arrhythmias, left-sided congestive heart failure, endocarditis, exercise intolerance, syncope, and sudden cardiac death. The greatest divergence between canine and human SAS clinical research has been the standard of care regarding treatment of these outcomes, with pharmacological intervention dominating best practices in veterinary medicine and surgical intervention comprising the standard practice for human SAS patients. Regardless of the species, the field has yet to identify a treatment option to prevent disease progression or permanently remove the fibrous ridge, but historical leaps in SAS research support a continued translational approach as the most promising method for achieving this goal.

Congenital heart disease: types, pathophysiology, diagnosis, and treatment options

“…While severe subaortic stenosis can result in exercise intolerance, dyspnea, chest pain, syncope, heart failure, and pulmonary edema. 232 The primary diagnostic method for subaortic stenosis is echocardiography, which can effectively evaluate the anatomy of left ventricle outflow tract, degree of subaortic stenosis, and function of the left ventricle. 230 Additionally, CMRI is useful for identifying and evaluating complex LVOTO anatomy, particularly in patients with poor acoustic windows.…”