Coarctation of the aorta in a neonate

Images Chris Harrington

A 11 day old presents to the Emergency department in acute respiratory distress. His mother states that his SOB has increased markedly over the past 24 hours.  While on the way to hospital he has an episode of tachypnea  cyanosis and not breathing for 5 seconds. He has been feeding poorly all day. He has not had a fever.

On examination he is in significant respiratory distress, RR 100/min  with increased work of breathing. He is sweaty and mottled. His peripheries are cool. The lower limb peripheries are cooler than the upper limbs. His central capillary return is 3 -4 sec. His distal capillary return 4 -5 sec. His upper limb BP is 90 mmHg systolic, his lower limbs 60 mmHg. He has hepatomegaly and pedal oedema

Iv access is obtained and he is given high flow oxygen.

Coarctation of the aorta is suspected.

A point of care ultrasound is performed.

These are the clips of his suprasternal notch without and then with colour Doppler

This is his lung ultrasound. More than 2 B lines are seen between 2 rib spaces highly suggestive of pulmonary oedema

PLAX view : The RV and LA appear big compared to the aortic root. They should be of approximately the same size.  The RV cavity is big compared to the LV cavity.

PSAX : There is flattening  towards the LV  of the interventricular septum (D shaped left ventricle).

Apical 4CV : the RV is almost the same size as the LV. There is poor longitudinal contraction of the LV. There is flattening of the interventricular septum in systole.

The subcostal view shows a fixed and dilated IVC

In summary, the baby has coarctation of the aorta with evidence of pulmonary oedema and right heart strain.

He is started on a prostaglandin infusion (prostin 10ng/kg/min) , is subsequently intubated and given ionotropic support in the neonatal intensive care.

Formal ultrasound confirmed a coarctation of the aorta 6 mm from the left subclavian artery, a PFO and a bicuspid aortic valve. No PDA was identified but by the end of the study a  small right to left shunt PDA was observed

Discussion

Coarctation of the aorta

  • 6 – 8% of all congenital heart disease
  • Affects 4/10.000 live births with a male predominance
  • Almost always associated with a diffuse arteriopathy

Associated anatomic abnormalities include:

  • bicuspid aortic valve (50 -60%)
  • mitral valve abnormalities
  • subaortic membrane
  • ventricular septal defect
  • patent ductus arteriosus
  • aortic arch abnormalities including aberrant subclavian arteries
  • 10% cerebral aneurysms in circle of Willis

Physiology:

  • Coarctation of the aorta (CoA)  is thought to develop from arterial ductal tissue extending into the aortic lumen.
  • In  utero, the ductus arteriosus diverts most of the right ventricular output (55%) away from the high resistance vascular bed to the low – resistance umbilical – placental circulation
  • After delivery, the increase in arterial PO2, the drop in circulating PGE2 and the drop in blood pressure within the lumen of the ductus (caused by the drop in pulmonary vascular resistance) promote closure of the ductus arteriosus.
  • Post natal closure in infants is effected in 2 phases : smooth muscle constriction producing “functional” closure of the lumen of the ductus within 18 to 24 hours after birth and “anatomical” occlusion of the lumen over the next few days or weeks
  • The wall of the ductus is made up of largely smooth muscle cells unlike that of the aorta and pulmonary trunk which is made of elastic fibres. Contraction of the smooth muscle cells present in the aortic coarctation results in narrowing of the aortic lumen and shortening of the ductus arteriosus. Thus constriction of the ductus arteriosus is accompanied by further obstruction postnatally
  • CoA  is challenging to diagnose at birth. It is the most missed diagnosis of congenital heart disease at birth. The diagnosis often delayed until the PDA closes. The patient then develops congestive cardiac failure in the first 2 -3 weeks of life
  • CoA may not fully develop until after the ductus arteriosus closes and constriction of the juxtaductal region occurs

Types of infantile coarctation and presentation

  1. Preductal : the narrowing is proximal to the ductus
  2. Ductal : the narrowing is at the level of the ductus – It usually appears when the ductus closes
  3. Postductal : The narrowing is distal to the insertion of the ductus. Even when the ductus is open , the blood flow to the lower extremities is impaired

Presentation in the neonate

  • Often severe
  • Usually asymptomatic at birth. Symptomatic day 4 to 10 when the ductus closes
  • LV failure +/- shock  once ductus closes

Clinically

  • Decreased feeding
  • SOB, tachypnea/recessions
  • Sweating
  • Vomiting
  • Lethargy / decreased LOC
  • Prolonged capillary refill in lower extremities
  • Absent femoral pulses (full pulses right arm)
  • Differential BP lower and upper extremities and right arm
  • Differential pre and post ductal oxygen saturations
  • Enlarged liver
  • Oliguria/anuria
  • Metabolic acidosis

Differential diagnosis of shock in the neonate

  • Coarctation of the aorta
  • Congenital adrenal hyperplasia
  • Infection/sepsis
  • Viral myocarditis
  • Addison’s disease
  • Other cardiac disease
  • Intraabdominal pathology such as volvulus
  • Causes of bleeding such as trauma/non accidental injury/vit K deficiency

Management

  • Good iv access
  • Diuretics or fluid resuscitation
  • Prostaglandin infusion (PGE1) 50ng/kg/min   (opens PDA and allows right to left shunt and flow to the lower limbs)
  • +/- ionotropic support  Dopamine 10 mcg/kg/min or dobutamine 10mcg/kg/min
  • Cover for sepsis if diagnosis not clear
  • +/- Intubate/ventilate
  • Maintain normothernia and normoglycaemia

 

References

  1. Med J Armed Forces India. 2003 Jul; 59(3): 228–233. Congestive Heart Failure in Infants and Children Mukti Sharma,* MNG Nair,+ SK Jatana,# and BN Shahi, PVSM, AVSM, VSM, PHS*
  2. Diagnosing Neonatal Aortic Coarctation in the Setting of Patent Ductus Arteriosus David M. Peng, MD, Rajesh Punn, MD, Katsuhide Maeda, MD, and Elif Seda Selamet Tierney, MD
  3. Science Direct Case Report Prostaglandin in aortic coarctation and closed arterial duct—treatment beyond ductal re-opening Ajay R. Desaia , Shreesha Maiyaa , David Inwaldb, Zdenek Slavika,n
  4. Archives of cardiovascular disease Review The ductus arteriosus: Physiology, regulation, and functional and congenital anomaliesLe canal artériel : physiologie, régulation, anomalies fonctionnelles et congénitales
  5. DIAGNOSTIC METHODS CONGENITAL HEART DISEASE Flow in the aorta and patent ductus arteriosus in infants with aortic atresia or aortic stenosis: a
    pulsed Doppler ultrasound study JOHN L. BASS, M.D., JAMES M. BERRY, AND STANLEY EINZIG, M.D., PH.D.
  6. Pediatr Rev. 2014 Oct; 35(10): 417–429.Respiratory Distress in the Newborn Suzanne Reuter, MD,* Chuanpit Moser, MD,† and Michelle Baack, MD*‡
  7. CLINICAL PRACTICE GUIDELINE Guideline coverage includes NICU KEMH, NICU PMH and NETS WACardiac: Coarctation of the Aorta (CoA) and Interrupted Aortic Arch (IAA
  8. Paediatric health review Volume 27, Issue 2, February 2017, Pages 83-89 Presentation of coarctation of the aorta in the neonates and the infant with short and long term implications Author links open overlay panel Gitika Joshi Greg Skinner Suhair  O.Shebani

 

 

 

 

 

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