Shone's syndrome

The Shone complex ( also called Shone 's syndrome) was first described in 1963 by JD Shone, along with several colleagues as a combination of congenital cardiac malformations that are evolutionarily logically connected. Since then, the common or partially occurrence of these individual components together as " Shone complex" is called. It is a rare congenital heart malformation. In the first description the following components have been identified:

  • Parachute mitral valve
  • Supravalvular membrane in the left atrium
  • A subaortic stenosis
  • A coarctation of the aorta

Today the term is broader and it is used for the combination of malformations of the left heart, which includes both the inflow into the left ventricle, the left ventricle itself, the outflow from the ventricle and the aortic arch. These include ( in direction of flow of the blood):

  • The Supravalvular mitral stenosis
  • Mitralklappenfehlbildungen as the parachute mitral valve or the hammock Valve
  • Hypoplasia ( underdevelopment ) of the left ventricle and / or a ventricular septal defect
  • A subaortic stenosis
  • Aortenklappenfehlbildungen ( with stenosis)
  • Underdevelopment of the aortic arch
  • A coarctation of the aorta

However, the full-blown disease with all of these malformations is rare and is very different in its expression. The diagnosis " Shone complex" is then asked if several of these components ( inlet and outlet of the left ventricle ) are present together. If, for example, before a coarctation of the aorta, must be sought in the diagnosis carefully for further malformations.

The malformations

  • The malformations of the mitral valve ( mitral stenosis Supravalvular, parachute mitral valve and Hammock - Valve ) have already been described.
  • The hypoplasia ( underdevelopment ) of the left ventricle occurs in fetal development the fact that not enough blood flows into the ventricle. She is the Shone complex relatively rare, but constitutes an essential factor for the long-term prognosis
  • Flows into the embryonic insufficient blood through the mitral valve into the left ventricle, the blood is looking for a " collateral circulation " through the foramen ovale and passes through the right atrium into the right ventricle. This increased blood in the right ventricle can lead to the great early heart development gap in the ventricular septum does not close. There remains a ventricular septal defect ( VSD). Since sufficient blood to flow through this defect into the left ventricle, hypoplasia of the chamber is prevented. Both the left ventricular hypoplasia and VSD occur relatively rarely, but are echocardiographically good to diagnose.
  • The subaortic stenosis is a narrowing of the outflow tract of the left ventricle below the flap. It occurs in many anatomic structures. When Shone complex following forms are essentially prove: a connective tissue membrane which extends from the septum to the Mitralklappensegeln. There is often also a small VSD
  • Additional Mitralklappengewebe with malformed mitral valve, with sail -like structures that protrude into the ventricle difficult, the outlet from the left ventricle
  • A tunnel-like stenosis, in which the ventricular septum ( septum ) is significantly thickened and the way the blood is hindered to the aorta
  • A displaced ventricular septum: the upper portion of the ventricular septum is not grown together during development to the lower portion. There is in addition a large VSD. The two first-named forms are often present, the latter rare. But all forms have in common is that they usually develop only during the first years of life of the child - Subaortenstenosen in infancy are extreme rarities.

Diagnostics

Therapy

If the suspicion of a Shone complex before, the therapeutic approach is individually planned carefully. Often, the coarctation is one of the " leading " symptoms. This can usually be expanded without surgery as part of a dilation with a cardiac catheter. If there are several intracardiac malformations, one tries so long zuzuwarten as it allows the clinical condition of the patient. In the surgery then necessary (using the heart -lung machine ) to be addressed as possible all / many of the individual components. The critical factor is often often fail to bypass the mitral valve and a replacement in the course of life. There is intraoperatively the risk of AV block, so that a pacemaker must be used. The early subaortic stenosis must be removed to avoid damage to the underlying aortic valve and aortic valve replacement is not always to be avoided.

Long-term prognosis

In all patients with Shone complex is expected to have numerous operations to good hemodynamic conditions achieved. But the goal is to keep the total number of operations as small as possible. In cases with borderline small left ventricle, there is the risk that the failure of the compliance chamber - despite anatomically good circumstances - a ( stauungsbedingte ) pulmonary hypertension persists, the long term the pulmonary vascular bed irreversibly damages and makes the prognosis doubtful. This remains as an option then only a combined heart -lung transplantation.

Lifetime check-ups are observed and also on the strict observance of endocarditis must be ensured.

  • Malformation
  • Disease in pediatric
Foramen ovale (heart) Atrioventricular block
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