Shone’s Syndrome is a form of heart disease that has two main features. First, there are multiple problems with the left side of the heart, which receives blood from the lungs and pumps it to the body. The valves and passageways are often too small or blocked. Second, the abnormal areas on the left side get worse over time. This second aspect of Shone’s Syndrome makes it very different from most other types of of congenital heart disease, which may be equally severe at birth, but do not progress over time.
Shone’s syndrome (also called Shone’s Complex, Shone’s Anomaly and Shones Syndrome) consists of a set of four cardiac defects: a supravalve mitral membrane (SVMM), parachute mitral valve, subaortic stenosis (membranous or muscular) and coarctation of the aorta. Essentially, it is both a left ventricular inflow and outflow obstruction. The prognosis is inversely related to the degree of obstruction caused by the SVMM. The SVMM is also first to develop and likely causes the development of the other three defects. Essentially it is also a stenosis or restriction of the aortic valve.
Shone’s complex is a very rare form of congenital heart disease. As a whole, the incidence of congenital heart disease is approximately 8 per 1000 live births. Since 1999 there have been less than 50 reported cases of Shone’s complex in the medical literature. There is no sex, racial, or ethnic predilection. The occurrence of these specific heart defects in future sibling after a previous child has been affected is slightly increased. This prompts many families to seek screening ultrasounds (also known as sonogram) of the fetal heart at 20 to 24 weeks of pregnancy.
Signs and Symptoms
Children with Shone’s complex can present with symptoms of congestive heart failure as early as the first week of life. Most children will exhibit symptoms by early childhood and few remain asymptomatic. Any or all of the following symptoms and signs may be seen:
- congestive heart failure
- shortness of breath
- swelling in the lower extremities
- weight gain from water retention
- fatigue
- failure to thrive, poor oral intake
- heart murmur from the associated narrowing of the aorta
- recurrent lower respiratory tract infections such as pneumonia
- pale color from the anemia.
Treatment
Making the diagnosis of Shone’s complex usually requires both an echocardiogram (ultrasound of the heart) and a cardiac catheterization procedure (insertion of a device through blood vessels in the groin to the heart that helps identify heart anatomy) performed by a pediatric cardiologist. The following heart anomalies are usually seen: abnormal (“parachute”) mitral heart valve, a supramitral ring (membrane that covers the mitral valve), subaortic stenosis (narrowing below the aortic valve) and coarctation of the aorta (narrowing of a section of the aorta). Routine blood tests such as a complete blood count, bleeding profile, and electrolytes may be obtained prior to cardiac catheterization. Once the diagnosis is established, a referral to a pediatric cardiothoracic surgeon for repair is usually made.
Prognosis
Current advances in cardiothoracic surgery have helped increase survival in recent times however the overall prognosis is still poor. Infection, stroke, heart block (interruption of the electrical activity of the heart) and chronic heart failure are frequent complications of repeated surgeries. A child’s course is closely related to the extent of mitral valve involvement and how well he or she tolerates the multiple corrective surgeries.
Source: Wikipedia.com and Christinacapozzifoundation.com and Madisonsfoundation.org