CXR showing dilated RVOT

CXR showing dilated RVOT

Chest X-ray PA view showing a bulge along the left border, below the aortic knuckle and pulmonary bay. Sternal wires are seen near the mid line, which would suggest that the person has possibly undergone a cardiac surgery by sternotomy.

Bulge below the pulmonary bay can be due to several reasons:

1. Prominent left atrial appendage as in severe mitral stenosis
2. Dilated right ventricular outflow tract as in Ebstein’s anomaly or endomyocardial fibrosis
3. Submitral left ventricular aneurysm
4. Bulge due to partial absence of left pericardium
5. Levoposed aorta in L-Transposition of great arteries.
6. Dilated RVOT (right ventricular outflow tract) can occur in case of severe pulmonary regurgitation after repair of Tetralogy of Fallot with a transannular patch.

The most likely possibility in this person with evidence of previous sternotomy is the last option. Davlouros PA et al, in a study of 85 patients after repair of tetralogy of Fallot, found right ventricular outflow tract aneurysm/akinesia in 56% of them [1]. This was documented by magnetic resonance imaging. RVOT aneurysm was noted in 16 patients while akinesia was found in 32 patients.

This non contractile region of the right ventricular outflow tract contributes to a decreased right ventricular ejection fraction. This finding was noted in those who did not have a patch in the RVOT also. Non contractile region in those who did not have a patch repair could be due to infundibular resection and interruption of the conal branch of right coronary artery [1].

Right ventricular outflow tract aneurysms late after repair of tetralogy of Fallot in adult patients has been associated with sustained ventricular tachycardia [2].

References

1. Davlouros PA, Kilner PJ, Hornung TS, Li W, Francis JM, Moon JC, Smith GC, Tat T, Pennell DJ, Gatzoulis MA. Right ventricular function in adults with repaired tetralogy of Fallot assessed with cardiovascular magnetic resonance imaging: detrimental role of right ventricular outflow aneurysms or akinesia and adverse right-to-left ventricular interaction. J Am Coll Cardiol. 2002 Dec 4;40(11):2044-52.
2. Harrison DA, Harris L, Siu SC, MacLoghlin CJ, Connelly MS, Webb GD, Downar E, McLaughlin PR, Williams WG. Sustained ventricular tachycardia in adult patients late after repair of tetralogy of Fallot. J Am Coll Cardiol. 1997 Nov 1;30(5):1368-73.