1. Dr. S. Ismat Bukhari
MD Resident
Dr. Ziauddin hospital
2. Introduction
• Coarctation of the aorta accounts for 5-8% of all congenital
heart defects.
• Coarctation of the aorta may occur as an isolated defect or in
association with various other lesions, most commonly
bicuspid aortic valve and ventricular septal defect (VSD).
3. Epidemiology
The prevalence of coarctation of the aorta appears to be
lower (< 2%) in Asian countries than in European and North
American countries.
• The prevalence of coarctation of the aorta in genetic
abnormalities such as Turner syndrome (45,X), is as high as
15-20%.
• Familial patterns of inheritance of coarctation have been
reported, as well as for other left heart obstructive lesions.
4. Mortality/Morbidity
Past autopsy studies suggest that the mortality rate in
patients in whom coarctation of the aorta is not surgically
repaired is 90% by age 50 years, with a mean age of 35
years.
In the current era, mortality is often determined by patient
age, patient size, and associated major cardiovascular
anomalies.
Associated problems that may contribute to death or
morbidity include hypertension, intracranial hemorrhage,
aortic rupture or dissection, endocarditis, and CHF.
5. Sex
• The male-to-female ratio is 2:1, although this ratio is not valid
in abdominal coarctation of the aorta, in which this rare lesion
predominantly affects females.
• The ratio of abdominal-to-thoracic coarctation is
approximately 1:1000.
• The male preponderance observed in older patients is not
seen in infants with coarctation of the aorta.
6. Age
• Generally, patients with coarctation of the aorta present early
in life with CHF or later in life with hypertension.
• Studies continue to document that coarctation of the aorta is
often missed in the first year of life, and the median age of
referral to a pediatric cardiologist in one study was 5 years.
7. Histological defect
• Coarctation of the aorta results from marked ridge like
thickening of the media of the aortic wall opposite the
insertion of the patent ductus arteriosus or ligamentum
arteriosum.
• This ridge or shelf becomes an obstruction when the patent
ductus involutes and when ductal tissue in the wall of the
aorta involutes.
8. • The diagnosis of coarctation of the aorta may be missed
unless an index of suspicion is maintained, and diagnosis is
often delayed until the patient develops congestive heart
failure, which is common in infants, or hypertension, which is
common in older children.
9. • In the past, coarctation of the aorta has been
described as:
– preductal (or infantile) type
– postductal (or adult) type
10. • The classic coarctation of the aorta is located in the thoracic
aorta distal to the origin of the left subclavian artery at about
the level of the ductal structure.
• However, rarely, a coarcted segment is present in the lower
thoracic or abdominal aorta.
12. • Dilatation of the descending aorta immediately distal to the
coarctation segment (poststenotic dilatation) is usually
present.
• Varying degrees of hypoplasia of the isthmus of the aorta (the
portion of the aorta between the origin of the left subclavian
artery and ductus arteriosus) are present in most patients
with thoracic coarctation; this hypoplasia may be significant
in symptomatic coarctation of the neonate and infant; in
children and adults, the isthmus may have only mild
narrowing.
13. • The transverse aortic arch (the arch between the
origin of the right innominate artery and the left
subclavian artery) is also hypoplastic in
symptomatic neonates and infants.
• Collateral vessels that connect arteries from the
upper part of the body to the vessels below the
level of coarctation may be seen; these may be
present as early as a few weeks to a few months
of life.
14. • The most commonly associated clinically significant defects
include patent ductus arteriosus, VSD, and aortic stenosis.
• Bicuspid aortic valve may be seen in nearly two thirds of
infants with coarctation of the aorta, whereas only 30% of
those who present in childhood have such an anomaly.
15. • Mitral valve anomalies, although less common than those of
the aortic valve, are also associated with coarctation of the
aorta.
• Sometimes, coarctation of the aorta is a complicating feature
of a more complex cyanotic heart defect, such as:
– Ttransposition of the great arteries
– Taussig-Bing anomaly
– Double-inlet left ventricle
– Tricuspid atresia with transposition of the great arteries
– Hypoplastic left heart syndrome.
16. • Some patients with coarctation of the aorta may have
cerebral aneurysms, predisposing them to cerebrovascular
accidents with severe hypertension later in life.
• Coarctation of the aorta is the most common cardiac defect
associated with Turner syndrome.
17. Pathophysiology
• Coarctation of the aorta imposes significant afterload on the
left ventricle (LV), which results in compensatory ventricular
hypertrophy.
• As the ductus (aortic end) constricts, the left ventricular
afterload rapidly increases, with a resultant increase in left
ventricular pressures (systolic and diastolic).
18. • This causes elevation of the left atrial pressure, which may
open the foramen ovale, causing left-to-right shunt and
dilatation of the right atrium and right ventricle.
19. Development of collateral circulation
• LV afterload may also gradually increase, allowing children
with less severe coarctation to develop arterial collateral
vessels that partially bypass the aortic obstruction.
• These children may be asymptomatic until hypertension is
detected or another complication develops.
21. Hypertension
• The mechanism for development of
hypertension is not clearly understood;
– mechanical obstruction
– renin-angiotensin mediated humoral mechanisms
22. • Activation of the renin-angiotensin system results in
vasoconstriction, cell hypertrophy, and the release of
aldosterone.
• Unlike most cases of CHF, coarctation of the aorta is more
complex because pre-coarctation and post-coarctation
hemodynamics are quite different.
23. Clinical presentation
• The presence of associated defects and aortic arch anomalies,
the extent of patency of the ductus arteriosus, the rapidity of
the process of closure of the ductus arteriosus, and the level
of pulmonary vascular resistance determine the timing of
clinical presentation and the severity of symptoms.
24. Early presentation
• Young patients may present in the first few weeks of life with;
– Poor feeding
– Tachypnea
– Lethargy
– Progression to overt CHF
– Shock.
• These patients may have appeared well prior to hospital
discharge, and deterioration coincides with closure of the
patent ductus arteriosus.
25. Physical findings in early presentation
• Tachypnea
• Tachycardia
• increased work of breathing
• Shock
• Blood pressue discrepancies between the upper and lower
extremities
• reduced or absent lower extremity pulses to palpation
• However, when the infant is in severe heart failure, all pulses are diminished.
• Upon treatment for heart failure, prominent brachial pulses with weak or
nonpalpable femoral arterial pulses may be discerned.
26. • In patients with an aberrant origin of the right subclavian
artery from the aorta distal to the obstruction, such
discrepancies in BP may not be present, although lower
extremity pulses are diminished versus the carotid pulses.
27. Murmur
• The murmur associated with coarctation of the aorta may be
nonspecific initially and is usually a systolic murmur in the left
infraclavicular area and under the left scapula.
• Additional murmurs that result from the presence of
associated abnormalities, such as VSD or aortic valve stenosis,
may also be detected.
• An ejection click may signify the presence of a bicuspid aortic
valve, whereas a gallop rhythm may indicate ventricular
dysfunction.
28. Late presentation
• Patients often present after the neonatal period
with hypertension or a murmur.
• These patients often have not developed overt
CHF because of the presence of arterial collateral
vessels.
• Diagnosis is often made after hypertension is
noted as an incidental finding during evaluation
of other problems.
29. • Other presenting symptoms may include;
– Headaches
– chest pain
– Fatigue
– life-threatening intracranial hemorrhage.
• True claudication is rare, although an occasional child
may experience pain or weakness in the legs.
• Palpation of femoral pulses and measurement of blood
pressure during routine examination is necessary to
avoid a delay in the diagnosis.
31. • Occasionally, the left arm pressure is lower than the right arm
pressure if the origin of the left subclavian artery is involved in
the coarctation.
• Similarly, anomalous origin of the right subclavian artery
(below the level of coarctation) may produce decreased or
absent right brachial pulse.
• Careful simultaneous palpation of upper and lower extremity
pulses may help confirm suspected coarctation.
32. • Blood pressure in both arms and one leg must be determined;
a pressure difference of more than 20 mm Hg in favor of the
arms may be considered evidence of coarctation of the
aorta.
• ejection click is found on auscultation
• A thrill may be present in the suprasternal notch or on the
precordium in the presence of significant aortic valve stenosis.
• In the rare case of abdominal coarctation, an abdominal bruit
may be noted.
33. Laboratory investigations
• Laboratory studies in neonatal patients who present in shock
include the following:
– Septic workup includes blood, urine
– cerebral spinal fluid (CSF) cultures.
– Electrolyte levels, BUN, creatinine, and glucose concentration.
• Measure arterial blood gases and serum lactate levels.
• Laboratory studies in older patients who present with
hypertension include urinalysis, electrolyte levels, BUN,
creatinine, and glucose concentrations.
34. Imaging studies
• Chest radiography in patients with early onset of
coarctation of the aorta may reveal cardiomegaly,
pulmonary edema, and other signs of congestive heart
failure.
• Radiography in patients with late onset of coarctation
of the aorta may reveal cardiomegaly.
• An inverted "3" sign of the barium-filled esophagus or
a "3" sign on a highly penetrated chest radiograph
(frontal view) may be visualized. Rib notching
secondary to collateral vessels may also be seen.
37. MRI and CT:
• Useful in older or postoperative patients to
assess residual arch obstruction, arch
hypoplasia, or formation of aneurysms.
38. Electrocardiography :
• in the neonate or infant with early onset of coarctation of the
aorta may reveal right ventricular rather than left ventricular
(LV) hypertrophy.
• ECG findings in patients with late onset of coarctation of the
aorta may be normal or may reveal LV hypertrophy and may
show signs of LV ischemia or strain.
• Sometimes, LV hypertrophy may manifest as increased S
waves in leads V5 and V6, the so-called posterobasal LV
hypertrophy.
39. • In the neonatal period , the ECG may reflect RVH rather than LVH. This is because the right ventricle in-
utero is the dominant ventricle, and through the PDA pumps blood to the descending aorta. Therefore,
coarctation of the aorta may cause an increase in the afterload of the RV as it will cause narrowing of the
aortic arch-descending aorta junction.
• This ECG, shows rsR' pattern in the right chest leads indicating RVH. In addition there are deep S waves in
the left chest leads.
40. • Cardiac catheterization is a prerequisite for
intervention in the form of either balloon
angioplasty or stent implantation in native or
recurrent coarctation.
41. • Selective aortic root or aortic arch angiography is necessary
to clearly demonstrate the aortic narrowing.
• Aortography is useful in demonstrating the type of aortic
coarctation (diffuse, long segment, aortic kinking
[pseudocoarctation]); extent of collateral circulation; the size
of ductus arteriosus, if patent; and the presence and degree
of hypoplasia of transverse aortic arch and aortic isthmus,
especially in neonates.
• LV angiography is particularly useful in neonates and infants
who demonstrate ventricular septal defects (VSDs) and in
evaluating LV function.
42. Treatment of early presentation
• Treatment in patients with congestive heart failure (CHF)
includes the use of diuretics and inotropic drugs.
• Prostaglandin E1 (0.05-0.15 mcg/kg/min) is infused
intravenously to open the ductus arteriosus.
• Ventilatory assistance is provided to patients with markedly
increased work of breathing.
43. Treatment of late presentation
• Treatment of hypertensionPreoperative hypertension can be
effectively treated using beta-blockers.
• The goal should be to reduce upper extremity hypertension,
but remember that vigorous attempts to achieve normal
upper extremity blood pressure (BP) may result in inadequate
lower-body perfusion.
• Beta-blocker therapy prior to surgery may reduce the severity
of postoperative hypertension, although most patients with
preoperative hypertension require at least transient
postoperative therapy.
44. • Evaluate associated abnormalities, such as aortic stenosis,
subaortic stenosis, or mitral valve disease.
• Evaluate adequacy of collateral blood vessels to assess the
safety of surgical intervention.
45. Surgical treatment
• At initial presentation, if cardiac failure or hypertension is the
presenting problem, it should be addressed to stabilize the
patient.
• Subsequently, the aortic obstruction should be relieved.
46. Pharmacotherapy
• The goals of pharmacotherapy are to reduce morbidity and
to prevent complications of coarctation of the aorta (CoA).
• Prostaglandin
• Inotropic agents
• Cardiac glycosides
• Diuretics
• Beta blockers
• Angiotensin converting enzyme inhibitor
• Vasodilators
47. Prostaglandins
• Identical to the naturally occurring prostaglandin E1 (PGE1) and
possesses various pharmacologic effects, including vasodilation and
inhibition of platelet aggregation.
• Used as palliative therapy to temporarily maintain patency of the
ductus arteriosus before surgery.
• Beneficial in infants with congenital defects that restrict pulmonary
or systemic blood flow and in patients who depend on a PDA for
adequate oxygenation and lower-body perfusion.
• Produces vasodilation and increases cardiac output. Each 1-mL
ampule contains 500 mcg/ml
48. Inotropic agents
• Used to stimulate alpha-receptor and beta-receptors in the
heart and vascular bed.
• Positive inotropic agents increase the force of contraction
of the myocardium and are used to treat acute and chronic
CHF.
• Some may also increase or decrease the heart rate (ie,
positive or negative chronotropic agents), provide
vasodilatation, or improve myocardial relaxation.
• These additional properties influence the choice of drug for
specific circumstances.
49. Cardiac glycosides (digoxin)
• These medications improve ventricular systolic function by
increasing the calcium supply available for myocyte
contraction.
50. Diuretics
• Promote excretion of water and electrolytes by the kidneys.
• They are used to treat heart failure or hepatic, renal, or
pulmonary disease when sodium and water retention have
resulted in edema or ascites.
• Generally includes a loop diuretic that inhibits sodium
chloride reabsorption in the ascending loop of Henle.
51. Beta blockers
• These agents inhibit chronotropic, inotropic, and vasodilatory
responses to beta-adrenergic stimulation.
• Preoperative hypertension can be treated effectively with
beta-blockers.
52. ACE inhibitors
• These agents reduce afterload and decrease myocardial
remodeling that worsens chronic heart failure.
• May be added if hypertension persists despite beta-blocker
therapy and no residual arch obstruction is noted.
53. Vasodilators
• Postoperative hypertension can be treated
short-term with vasodilators, which reduce
systemic vascular resistance, allowing more
forward flow, thus improving cardiac output.
54. Follow up
• Focus postoperative recovery of patients
• control of blood pressure (BP)
• slow advancement of diet
• manipulation of antihypertensive medications
• progressive ambulation
• pulmonary therapy to improve left lung atelectasis (common
after left thoracotomy)
55. Outpatient care
• Focus early outpatient follow-up care on wound healing, resolution of lung
atelectasis, and adjustment of antihypertensive medications.
• Assess postoperative BP response to exercise prior to discontinuation of
antihypertensive therapy.
• Many patients may be weaned from antihypertensive therapy over months or
years following repair of coarctation.
• Other patients may require some form of ongoing antihypertensive therapy.
• Search for late complications of coarctation repair, including recurrent coarctation
and aneurysm formation.
• Patients should receive antibiotic prophylaxis before undergoing any bacteremia-
producing surgery or procedures, especially in view of reported incidence of
bacterial endocarditis during follow-up.
56. Prevention of complications
• Fetal echocardiography is indicated during pregnancy in every
woman who has previously borne a child with congenital
heart disease (CHD), especially left heart obstructive lesions.
• Postnatally, early detection of coarctation of the aorta is
important to avoid prolonged hypertension or other
complications.
• Careful measurement of BPs and evaluation of lower
extremity pulses in newborns and at subsequent healthy child
examinations is imperative.
57. Complications
• Coarctation of the aorta is a lifelong disease with complications that may
not be evident until many years following an initial and apparently
successful repair.
• Recurrent coarctationRecurrence of coarctation is associated with patient
size, age at surgery, and associated transverse arch or isthmic hypoplasia.
• Ductal tissue in the wall of the aorta may involute and contribute to
recurrence, as might scarring at the repair site.
58. • Some surgeons believe that the use of interrupted sutures in
the anterior portion of the anastomotic suture line improves
aortic growth and reduces the risk of recurrence.
• Sometimes, the surgical repair site is unobstructed, yet
obstruction develops at the transverse arch or isthmus
because of the failure of these areas to grow proportionally to
the rest of the arch.
59. Hypertension
• Related to alterations in the renin-angiotensin system and
baroreceptors.
• As with other forms of uncontrolled hypertension, patients
may be at risk for premature atherosclerosis, ventricular
dysfunction, and rupture of cerebral aneurysms.
60. Cerebral aneurysms
• Berry aneurysms of the circle of Willis or other vessels are
believed to occur in as many as 10% of patients with
coarctation of the aorta and may be multiple.
• Aneurysm size tends to increase with age, as does the risk of
rupture.
• Uncontrolled hypertension promotes the growth of the
aneurysms and increases risk of rupture.
61. • Most patients are asymptomatic until rupture occurs,
although some aneurysms may leak prior to rupture, resulting
in warning symptoms of headache, photophobia, weakness,
or other symptoms.
• Rupture of a cerebral aneurysm is associated with high
mortality rates and should prompt repair of both the
aneurysm and coarctation.
62. Paralysis
• Paraplegia can occur from spinal cord ischemia, resulting from
a compromised blood supply to the anterior spinal artery.
• Risk of paralysis is increased with reduced arterial collateral
vessels, prolonged aortic cross-clamping time, and
intraoperative sacrifice of intercostal arteries, as well as other
factors.
63. • Cardiomyopathy is usually present in infants with critical
coarctation, especially if additional levels of left heart obstruction,
such as aortic stenosis or subaortic stenosis, are present.
• Some patients may have changes of endocardial fibroelastosis that
result in chronic dilated cardiomyopathy, requiring medical
management or, in rare cases, cardiac transplantation.
• Hypertrophic cardiomyopathic changes also may occur,
predisposing the patient to subendocardial ischemia, arrhythmias,
or congestive heart failure (CHF) related to diastolic dysfunction.
64. Chlyothorax
• Extensive dissection at surgery may result in disruption of
the thoracic duct, leading to chylothorax.
• Chylothorax is recognized when feedings are instituted
postoperatively.
• Persistent chylous pleural effusions may necessitate long-
term chest tube drainage.
• Some patients respond to dietary therapy with medium-
chain triglyceride diet, fat restriction, and/or total parental
nutrition. Patients with refractory chylothorax may require
pleurodesis or thoracic duct ligation.
65. Post-coarctectomy syndrome
• Restoring pulsatile blood flow to the mesenteric arteries may
result in mesenteric arteritis, in which the arteries become
distended and may rupture.
• Reflex arteriolar vasoconstriction occurs as part of
autoregulation of blood flow and can result in ischemia.
• Clinical manifestations may range from mild abdominal
discomfort to an acute abdomen with severe abdominal
distention, vomiting, ileus, and progression to intestinal wall
hemorrhage or perforation.
66. • Thus, feedings are usually delayed for 48 hours after surgery, and
nasogastric tube decompression is continued until feedings are begun
slowly and advanced as tolerated.
• Patients with severe postcoarctectomy syndrome may require exploratory
laparotomy for treatment of bowel necrosis or perforation.
• Careful monitoring and good control of BP in the postoperative period
may reduce the risk of postcoarctectomy syndrome.
67. Valvular stenosis
• Valvar aortic stenosis, membranous subaortic
stenosis, and mitral valve stenosis: These may
develop during the follow-up period; if these
are significant, transcatheter or surgical relief
of the obstruction may become necessary.
68. Prognosis
• Coarctation of the aorta is a lifelong disease with a guarded
prognosis.
• Relief of obstruction, control of hypertension, follow-up monitoring
for recurrent obstruction, and follow-up care of associated
anomalies are imperative.
• Continue subacute bacterial endocarditis prophylaxis indefinitely,
even in the absence of associated abnormalities.
• Patients without residual obstruction who are normotensive both at
rest and with exercise should lead normally active lives without
restriction. They should be able to obtain health and life insurance.
69. • Patients with persistent hypertension, untreated residual
obstruction, or other complications have a variable
prognosis related to the severity of these problems.
• Death appears to be secondary to recoarctation repair,
aneurysms at site of coarctation repair or at a remote site,
congestive heart failure, bacterial endocarditis, and
hypertension.
• Attempts to define factors that affect long-term survival
have been made; age at operation and degree and duration
of hypertension prior to surgery appear to affect the long-
term survival.