What is HLHS and Shone's Syndrome?
February 21, 2006
Hypoplastic Left Heart Syndrome is a defect where the left side of the heart -- the aorta, aortic valve, left ventricle and mitral valve -- is underdeveloped.
Shone's 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.
Jack’s condition was originally categorized as HLHS variant and not as severe as a classical case of HLHS, since he was born with a small left ventricle. However, it has since been redefined as Shone’s Syndrome, which is basically a subset of HLHS.
To fix his heart defect, Jack will need a series of procedures. He had the first surgery, called the Norwood Procedure on He has since been recommended for the Bi-Ventricular repair but needed an intermediary surgery to close his VSDs (holes in heart), repair his mitrial valve and restrict the blood flow out of his ASD before attempting the Bi-Ventrical repair.
These surgeries are one of the great achievements of congenital heart surgery. Considering Jack’s recovery and development to date, his chances of living a normal, healthy life are spectacular!
