Shone syndrome

Shone syndrome, also known as Shone complex, is a rare syndrome characterized by left-sided, obstructive congenital heart defects.

Epidemiology

Shone syndrome is thought to be very rare, accounting for less than 1% of all congenital heart disease ¹.

Clinical presentation

Patients, usually neonates and infants, present with signs and symptoms of congestive cardiac failure ^1-3. On clinical examination, patients may have murmurs heard over both the aortic and mitral areas during precordial auscultation ⁴.

Pathology

The complete Shone syndrome consists of four cardinal left-sided cardiac defects:  

• supravalvular mitral membrane ^1-3
• subvalvular aortic stenosis (membranous or muscular) ^1-3
• parachute mitral valve ^1-3
• coarctation of the aorta ^1-3

Although four features were originally described, it is more common for patients to have incomplete Shone syndrome with only some of the obstructive lesions ³. 

Radiographic features

Case studies have utilized both echocardiography and CT in order to identify each of the four obstructive cardiac defects in Shone syndrome ^1,4. 

See individual articles for a detailed description of each defect.

Treatment and prognosis

Surgical intervention is required in all cases ^2,3. Generally, patients will need multiple surgeries at initial presentation, as well as repeated surgeries throughout their life ^2,3.

History and etymology

The syndrome is named after John D Shone (1924-2002), an English pediatric cardiologist, who described the constellation of features in his 1963 seminal paper ⁵.