Congenital Anormaly Of The Heart: Coarctation Of Aorta
This condition is characterized by obstruction of the aorta in the region of the ductus arteriosus or ligamentum arteriosum just distal to the left subclavian artery. Very rarely it may occur at a more proximal site in the arch or in abdominal aorta. In the majority of cases, coarctation occurs as a discrete infolding of the dorsal, aortic wall. In about 20% of cases, coarctation exists as the only abnormality, whereas the rest have associated abnormalities like bicuspid aortic valve, ventricular septal defect, atrial septal defect, mitral stenosis, mitral regurgitation, and transposition of great vessels. Bicuspid aortic valve is the commonest associated anomaly, majority of them being hemodynamically insignificant. When coarctation is severe, arterial blood from the proximal part is taken to the distal part through collateral circulation which develops from the intercostals arteries and the subclavian system.
Approximately 50% of coarctation present in the neonatal period, many of them with varying degrees of heart failure. Those who present during adolescence and adulthood give history of intermittent claudication of legs, mild fatigue and dypsnea. In older individuals, it may present as congestive heart failure. Disproportionate development of the arms, chest and shoulder girdle compared to the legs may be boted in some patients. The upper limb pulses, suprasternal pulse, and carotid pulse are prominent and the blood pressure is high in the arms. The femoral pulse is felt feebly and is delayed. The apex beat may be heaving in nature. Usually, there is an ejection systolic murmur with a constant ejection click, best heard over the right sterna border. This is caused by the associated bicuspid aortic valve. Sometimes, there may be an early diastolic murmur of aortic incompetence. The collateral as may be visible and palpable over the back of the chest, around the scapula, and sometimes in front of the chest. Continuous murmur may be produced from the site of coarctation or from the collaterals.
What To Do Next!
How to treat Coarctation Of The Aorta
Diagnosis And Treatment
The diagnosis should be suspected by the finding of absence or delay of the femoral pulses, presence of high blood pressure in the upper limbs, low blood pressure in the lower limbs, and the cardiac abnormalities. X-ray chest shows the coarctation as a narrowing in the course of the aorta with dilatation above and below (the ‘3’ sign). Electrocardiogram show evidence of left ventricular hypertrophy. Cardiac catheterization and aortography reveal the defect.
During the neonatal period, intensive medical therapy is given to control congestive heart failure. If the congestive heart failure is not amenable to medical therapy, surgical treatment is considered. In those cases who respond to medical therapy, surgical treatment is considered. In those cases who respond to medical treatment elective surgery is planned usually between the ages of 8-12 years. The present trend is to perform surgery early because residual hypertension is less in such cases. Surgical treatment consists of removal of the affected segment and reconstruction. In cases where surgery is delayed unduly, the hypertension leads to secondary damage to the kidney and therefore even after surgery the hypertension persists.
© 2014 Funom Theophilus Makama