1. Flow reversal in arch of aorta
Dr Neeraj Aggarwal
Paediatric Cardiologist
Department of Paediatric Cardiac Sciences
Sir Ganga Ram Hospital, New Delhi

3. Common causes
Communication between the ascending aorta, the proximal aortic arch or its branches, and a lower pressure chamber or channel (such as pulmonary vessels, ventricles, or systemic veins), that results in stealing of blood from the distal aortic arch and descending aorta
Examples – Aorto - pulmonary window, severe AR, Arteriovenous (A-V) malformation of the head and neck vessels, coronary artery fistula and systemic to pulmonary fistula
2. Severe LVOT obstruction such as critical AS or HLHS

4. Case 1- Aorto Pulmonary Window
4 month old ,presented with ARDS and Pneumothorax-kept on high frequency ventilation
Past history of recurrent chest infections and failure to thrive
On examination- bounding pulses, Ejection systolic murmur ,heart sound not clear.
CXR – cardiomegaly (CT ratio -60%)
Echo- very poor images in subcostal and thoracic windows and no diagnosis could me made.
Suprasternal window –No PDA, reversal In arch present

6. CT angiogram -AP window

7. Case 2 (2 patients) - Vein of Galen malformation
Neonate - 2 days old
Admitted with Congestive heart failure
Echo –PFO and PDA right to left , PAH , reversal in arch
Further interrogation –prominent innominate vessels, SVC flow increased
Cranial bruit present
Suspected cranial Arterio-venous malformation-confirmed by cranial USG and MRI

8. Echo –SVC flow

9. PFO and PDA right to left

11. Case 3-Critical AS Neonate 1 day old, presented with shock
Echo showed LVEF 10 % with restricted aortic valve opening (PG 16 mmhg),PDA shunting BD
Reversal in aortic arch

12. Case 3-Critical AS Underwent Balloon aortic dilatation
Post procedure echo – no reversal in arch
Ejection fraction takes time to recover but reversal subsided immediately
May suggest improved Left ventricular cardiac output

13. Critical AS

14. Before and after BAV

15. Case 4-Truncus arteriosus
5 year old male, Failure to thrive, recurrent chest infections, loud P2
CXR-Cardiomegaly, high Qp, saturations 94 %
Echo –Truncus arteriosus type 1,no Truncal valve regurgitation, reversal in arch (indicating low PVR )
Oximetry studies –not useful

16. CXR and Echo

17. Case - Truncus arteriosus
Underwent complete repair
Patient extubated on table in OT
Pre discharge echo –mild TR ,PG 35 mmhg
Discharged on 7th post operative day

18. Case 5- Anomalous origin of RPA from aorta
6 yr old female child ,with recurrent chest infections and not growing well
Diagnosed as RPA origin from aorta ,MPA continued as LPA with large PDA, no intracardiac shunts
Clinical data shows operability (saturation -95 % in both upper limbs and 93 in lower limbs , CXR- Cardiomegaly with high Qp )

19. CXR PA view

20. Echo

21. Anomalous origin of RPA from aorta
Reversal in arch of aorta –indicates low resistance in RPA
Lack of differential saturation between upper and lower limbs indicates LPA having hyperkinetic PAH
In OT- temporary occlusion of PDA led to fall in LPA pressure {from 95/48(68) to 57/21(37) }
Patient underwent surgical repair with unifocalization of RPA to MPA.
Patient extubated in OT .
Pre discharge echo showed mild TR ,PG of 30 mmhg

22. Case 6 –Obstructed TAPVC
2 weeks old neonate, diagnosed with obstructed supra cardiac TAPVC, restrictive PFO,PDA shunting right to left.
Severe PAH with reversal in arch
Cranial auscultation –no bruit, USG brain –no cranial AV malformation

24. Case 6 –obstructed TAPVC
TAPVC repaired
Post op echo –no reversal in arch
Hypothesis- PAH with low cardiac index can lead to reversal in arch

25. Case -7 Neonatal PAH
Full term neonate ,meconium aspiration ,kept on ventilator
Echo –PPHN, PFO BD shunt ,PDA right to left shunt ,systolic function normal, reversal in arch
Patient needed pulmonary vasodilators ,high frequency ventilation and NO ventilation

26. Neonatal PAH Cranial auscultation and USG skull normal After 14 days
patient improved ,could be weaned from High frequency ventilator and NO and
Echo showed loss of reversal in arch along with fall in PA pressures
Patient was finally extubated after 1 month.

27. Case 7-B-- PPHN Almost same presentation Family refused for ECMO
Patient succumbed to disease on day 14 of life

28. Case 9-ALCAPA
40 yr old female with DOE class 2,echo showed moderate MR, No AR and LVEF 55 % ,on follow up since last few yrs at many institutions

29. Conclusion
Flow Reversal in arch of aorta can be correlated for supportive evidence in various diagnostic and operability dilemmas as in Truncus arteriosus, Hemitruncus and AP window.
Cerebral AVM can be suspected on the basis of echocardiogram
Low cardiac output associated with PPHN may lead to reversal in arch in neonates and may guide for early aggressive therapy
loss of “reversal in arch” after BAV in critical AS after may be taken as additional marker for improvement in LV output( before LV function starts improving)
Non cardiac lesions like severe septicaemia with low SVR can also lead to reversal in arch and should be clinically judged.

30. Thank You