Aortic Valve Stenosis

Subvalvular Aortic Stenosis: Learning From Human and Canine Clinical Research

“…Several life-threatening effects can stem from these inciting changes. Potential adverse outcomes of SAS include arrhythmias, left-sided congestive heart failure, endocarditis, exercise intolerance, syncope, and sudden death (due to ventricular arrhythmias from the subendocardial ischemic/fibrotic changes) [ 5 , 46 ]. In fact, the average lifespan of dogs with severe SAS is a mere 19 months without clinical intervention [ 47 ].…”

“…The key feature of an echocardiographic evaluation of dogs with SAS is an assessment of the LVOT and the stenotic region below the aortic valve via two-dimensional (2D), M-mode, and Doppler imaging, as described in published guidelines [ 43 , 49 ]. This includes right parasternal long-axis views (to screen for a fibrous ridge/ring of fibrous tissue in the LVOT, evaluate heart chamber size and shape, and assess whether there is post-stenotic aortic dilatation), right parasternal short-axis views (to screen for any LVOT narrowing and/or valvular pathology by measuring the diameter at the aortic valve hinge points), and subcostal views (to quantify the maximum LVOT velocity, or aortic velocity, via continuous-wave Doppler measurement) [ 46 ]. Left apical continuous wave Doppler imaging is considered an acceptable alternative when subcostal imaging is impaired.…”

“…Left apical continuous wave Doppler imaging is considered an acceptable alternative when subcostal imaging is impaired. Color flow, pulsed wave, and continuous wave Doppler imaging techniques are employed to gauge stenosis severity, to evaluate the presence and magnitude of aortic regurgitation (if any), to assess myocardial function, and to rule out other congenital defects [ 46 ]. The severity of a case is defined by the measured aortic velocity and calculated pressure gradient.…”