Anatomy Patients with mitral stenosis and aortic stenosis are often referred to as having Shone’s syndrome, although as originally described Shone’s syndrome has four necessary components. Shone’s complex is a term that connotes 2-3 of the components.
- Supramitral membrane in the left atrium. In the most extreme cases, this may be a stenosing, perforated diaphragm above the mitral valve at the mitral annulus. More commonly, this represents a non-obstructive ridge.
- Parachute deformity of MV. Papillary muscles converge on a single papillary head (or narrowly spaced papillaries), which limits MV opening.
- Subaortic stenosis. Usually associated with subaortic flow acceleration due to marked focal hypertrophy (bulging) of the basal anterior ventricular septum, resulting in a fibrous ridge on top of the muscular bulge.
- Coarctation of aorta
Clinically, Shone’s syndrome often creates mitral stenosis, LA hypertension, and restrictive LV physiology. More severe cases fall along the HLHS spectrum of disease.
Combined atrial arterial switch operation (double switch) for hearts with Shone syndrome and pulmonary hypertension