Congenital Heart Disease part 4

COARCTATION OF THE AORTA

Coarctation of the aorta is considered as part of a generalized  arteriopathy, and not only as a circumscript  narrowing of the aorta. Its occurs as a discrete stenosis or as along, hypoplastic aortic segment. Typically coarctation of the aorta is located in the area where the ductus arteriosus inserts, and only in rare cases occurs ectopically (ascending, descending or abdominal aorta).

Associated lesions include bicuspid aortic valve, subvalvular, valvular or supravalvular aortic stenosis, mitral valve stenosis (parachute mitral valve, a complex known as Shone syndrome), or complex congenital heart defects. Coarctation aorta can be associated with Turner, Williams-Beuren, or congenital rubella syndromes, neurofibromatosis, Takayasu aortitis or trauma.

Coarctation aorta imposes significant afterload on the left ventricle, resulting in increase wall stress, compensatory left ventricular hypertrophy, left venticle dysfuctions, and the development of arterial collaterals.

Cystic medial necrosis with early elastic fibre fragmentation and fibrosis was found in the ascendings and decendings aorta, resulting in an increased stiffness of the aorta and carotid arteries.
Sign and symptoms depends on the severity of the coarctation of the aorta. Patients with serious coartation of the aorta exhibit signs and symptoms early in life, while particularly mild cases may not become evident until adulhood.

Key symptoms may include headache, nosebleed, dizziness, tinnitus, shortness of breath, abdominal angina, claudication, leg cramps, exertional leg fatigue and cold feet.

The natural course may be complicated by left heart failure, intracranial haemorhagge (from berry aneurysm), infective endocarditis, aortic rupture/dissection, premature coronary and cerebral artery disease, and associated heart disease.

In native coarctation of the aorta with appropriate anatomy, stenting has become the treatment  of first choice in adults in many centres. For adults with recurring or residual coarctation of the aorta, angioplasty with or without  stent implantation has been shown to be effective in experienced hands, and preferably stenting has also become first choice if anatomy is appropriate.

MARFAN SYNDROME

Marfan syndrome is an autosomal dominant disorder of connective tissue, in which cardiovascular, skin and skeletal, ocular, pulmonary and dura mater abnormalities may be present to a highly variable degree.

Prognosis is mainly determined by progressive dilatation of the aorta, leading to aortic dissection or rupture, which are the major causes of death. The rate of dilatation is heterogeneous and unpredictable. The risk of type A dissecton clearly increases within increasing  aortic root diameter, but dissection may occasionally occur even in patients with only mild aortic dilatation. Other parts of the aorta may also be dilated . Patients with dilated aorta are usually asymptomatic. The presence of significant aortic, tricuspid, or mitral regurgitation may lead to symptoms of ventricular volume overload, but left ventricle disease may also occur independently.

Early identification and establishment of the diagnosis is critical, since prophylactic surgery can prevent aortic dissection and rupture.