Coarctation of the aorta is a congenital heart defect in which a segment of the aorta is narrowed. Depending on the severity of the coarctation, it may present as a critical neonatal disease or it can remain asymptomatic for years.
Milder forms of coarctation may not present in signs or symptoms during infancy. As children become older, they may experience chest pain, headache, fatigue, poor growth, dyspnea, dizziness, fainting, and claudication of the lower extremities. Complications such as heart failure are usually rare.
In extreme cases, critical coarctation manifests soon after the closure of the ductus arteriosus. These neonates present with irritability, dyspnea, poor feeding, and diaphoresis. Serious complications include shock , renal dysfunction, and metabolic acidosis. The clinical picture resembles that of sepsis.
The blood pressure disparity in the upper and lower body is characteristic. Upper extremities exhibit elevated blood pressure and strong pulses ; whereas the lower extremity has low or immeasurable blood pressure and reduced femoral pulses.
On auscultation, a systolic ejection murmur is heard at the upper left sternal border and left axilla. It may also be present at the left scapular area. Furthermore, a systolic ejection murmur is heard in cases with coexisting bicuspid aortic valve.
Since disorders such as Turner syndrome, DiGeorge Syndrome, and others can be present, their features will also manifest.
The clinician should obtain a thorough history and physical exam. The following studies will establish the diagnosis:
Chest radiography identifies cardiomegaly as well as the coarctation. An echocardiogram demonstrates the site and degree of severity. Additionally, it provides key findings such as valvular disease, cardiac function, etc.
Further testing such as the electrocardiogram (ECG) can depict ventricular hypertrophy if present. Moreover, magnetic resonance imaging (MRI) indicates the location of the defect and assesses its effects on blood vessels  while a computed tomography (CT) angiogram evaluates the arteries to determine narrowing of the aorta . Finally, cardiac catheterization and aortography may also be applied.
Neonates presenting with symptoms should be treated with prostaglandin E 1 to reopen the ductus arteriosus . If the latter remains open, the pulmonary artery bypasses the coarctation, which subsequently improves blood supply and corrects the metabolic acidosis. Additionally, diuretics can relieve symptoms secondary to heart failure. Oxygen supplementation in these patients should be used carefully since it can alter the pulmonary hemodynamics. In coarctation manifesting with left ventricle failure, dobutamine or other therapies may be utilized.
In stable patients, hypertension treatment consists of beta blockers. Post correction, there are numerous alternatives such as ACE inhibitors, angiotensin II receptor inhibitors, and calcium channel blockers .
The surgery of choice is debatable. Many institutions will initially repair the coarctation while others perform balloon angioplasty with or without stents as the first intervention. In cases with recurrence, the latter may be performed. Of importance, successful outcomes with angioplasty have been demonstrated in both initial and recurrent coarctation (73% and 80%, respectively).
Specific surgical interventions include resection of the coarctation followed by anastomosis of the unattached segments. Also, there are various forms of aortoplasty depending on the anatomy. Marked cases may need widening of the isthmus and transverse segments of the aorta .
Surgical planning and decision making revolve around the particular case and expertise.
The prognosis is good for patients with coarctation of aorta without other cardiac defects. These patients are treated for hypertension with standard drugs such as beta blockers, ACE inhibitors, angiotensin II receptor blockers, and others . However, patients with coexisting cardiac anomalies exhibit a greater risk for chronic complications.
Recurrence is observed in surgically corrected patients. Hence, periodic monitoring is paramount. Additionally, due to the higher occurrence rate of coronary artery disease, all patients require surveillance.
For symptomatic infants, the post surgery mortality rate is below 5%. This number is even less in children, namely under 1% .
The cause of this defect is likely a multifactorial inheritance in origin as are the majority of congenital heart diseases . Although many cases are sporadic, it has been observed in a familial pattern. Furthermore, coarctation has been associated with Turner Syndrome and other genetic diseases.
Several theories have been hypothesized regarding the development of coarctation of the aorta. One explanation suggests that modification of intrauterine blood and the resultant flow through the aortic arch causes coarctation . Another proposes that ductal constriction after birth contributes to the formation of coarctation . Furthermore, one theory postulates that tissue from the ductus arteriosus blends with that of the aorta. Hence, when the ductus closes after birth, the extra tissue narrows the aorta.
Coarctation of the aorta accounts for 6% to 8% of all congenital heart defects . Regarding gender, it is observed more in males than females. This congenital heart defect often manifests in conjunction with a ventral septal defect, aortic valve abnormalities, and other cardiac malformations. It is present in 15% to 20% of Turner syndrome open link patients. Additionally, it is also found in hypoplastic left heart syndrome, Shone's complex, and DiGeorge syndrome . This cardiac defect appears to have a seasonal preference as it occurs more in September and November.
Cardiovascular changes with coarctation
This congenital defect is due to the narrowing of the aorta. The coarctation in most cases occurs after the arteries supplying the upper body branch off. While this spares the blood flow to the head and arms, there is reduced flow to the lower extremities. This causes the observed blood pressure discrepancy between the upper and lower halves of the body.
Since the narrowing of the aorta limits blood flow out of the left ventricle, the blood backs up in this chamber. As a result, structural adaptations such as left ventricular hypertrophy occurs. Severe cases of coarctation develop left ventricular failure and congestive heart failure.
Medical implications of coarctation
The impact of the aortic coarctation is related to the degree of narrowing of the aortic arch and its effect on the afterload.
Mild and moderate narrowing can remain asymptomatic for years. However, the resultant chronic hypertension is accompanied by medical complications even in cases where the coarctation is surgically corrected.
Coarctation repair is performed in cases with congenital heart failure (CHF), systolic hypertension, or peak pressure gradient across the coarctation measured to be greater than 20mmg Hg .
Endocarditis prophylactic treatment is indicated for 6 months post repair. Well-child doctor appointments include palpation of pulses, particularly that of the femoral artery. Blood pressures should be obtained and if there is a discrepancy in pulses or hypertension, this warrants measurements in all extremities. For patients with cardiac defects, thorough evaluation with an echocardiogram is essential. Additionally, surveillance includes screening for brain aneurysms. Patients with presentations suggestive of coexisting genetic disorders or other cardiac anomalies can undergo genetic evaluation. Aortic valvular abnormalities should prompt evaluation of family members. Patients with a berry aneurysm and hypertension should have blood pressure measurements on upper and lower extremities.
Coarctation of the aorta is a common congenital cardiac defect characterized by narrowing of the descending aorta, typically near the ductus of arteriosus. Due to the anatomical location of the narrowing, the arterial branches that supply the upper extremities are spared  . However, circulation to the lower body is impaired, hence the marked discrepancy in the blood pressure and pulses between the two halves of the body.
Coarctation can occur as an isolated anomaly or in conjunction with manifestations such as ventral septal defect, bicuspid aortic valve, or other left ventricular outflow tract obstructive lesions. Furthermore, it has been observed with familial patterns as well as sporadically.
Hypertension is a consequence of this defect and requires treatment whether through surgery or standard antihypertensives. Additionally, significant coarctation leads to pathophysiologic and cardiac structural modifications that may culminate in heart failure.
Diagnosis is established through a comprehensive evaluation consisting of history, physical examination, and imaging such as an echocardiogram, chest radiograph, and others as well, if indicated.
Correction of the coarctation is conducted through surgery or balloon angioplasty. All patients require surveillance since recurrence and other coexisting cardiac anomalies may present complications.
The aorta is the major blood vessel coming out of the heart which leads the blood to the body. Coarctation of the aorta is the narrowing of a segment of this blood vessel that occurs as a birth defect before birth. It is one of the most common heart defects. It is typically diagnosed in babies, children, or adults younger than 40 years old.
While the cause is not exactly known, sometimes it runs in families. Other times, it occurs randomly. Coarctation may present as a single heart abnormality, or can occur with other defects such as bicuspid aortic valve, ventral septal defect, and others.
The narrow part of the aorta causes reduced blood pressure in the lower half of the body. However, the upper body will have higher blood pressures. Likewise, there are diminished pulses in the lower body.
Newborns with severe narrowing experience symptoms such as fussiness, sweating, difficulty in breathing, rapid breathing, problems with eating, pale skin, etc. They are very ill and require medicine and surgery.
Diagnosis is achieved through assessment of the patient including a history, physical exam, and imaging of the heart. The history includes any signs and symptoms and further information. The physical exam reveals higher blood pressures in the top half of the body and lower blood pressures in the bottom half. Also, the pulses are reduced or absent in the lower body. The doctor will also listen to the patient's heart with a stethoscope to determine if there are abnormal heart sounds or murmurs.
The imaging consists of an echocardiogram, which is the ultrasound of the heart. It will show the narrowing of the aorta and any other problems. A chest x ray and other tests may be performed as well.
Treatment is usually surgery, but the timing and type of procedure depends on the severity and the expertise of the clinician. One surgery uses a balloon to widen the aorta. Another surgery involves removing the narrow part and then connecting the free ends. In addition, since coarctation causes high blood pressures, medicine will be used for control.