Teaching Case

Section

Cardiovascular

Case Type

Clinical Cases

Authors

A.H. Porooshani J. Ball J.M. Wide Whiston Hospital, St Helen's and Knowsley NHS Trust, Merseyside L35 5DR

Patient

57 years, female

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Clinical History

Long increasing history of dyspnoea with further more acute symptoms.

Differential Diagnosis List

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Iatrogenic SVC to left atrial fistula

Imaging Findings

Admitted to hospital complaining of acute on chronic dyspnoea and chest pain. She had closure of ASD at 16, two small CVAs in her early 50s and admissions with chest pain with a negative ETT and coronary angiogram at the age of 52. She was not cyanosed or clubbed and had low oxygen saturations. Normal chest and cardiac examination. Her ECG and CXR was normal. A lung perfusion scan showed minimal uptake in the lungs with accumulation of radionuclide in the brain, spleen, kidneys and soft tissues (picture 1). A right to left intra cardiac shunt was suggested . She had a normal echocardiogram . A CTPA was performed but after two attempts it failed to demonstrate the pulmonary vasculature. A month later attending clinic she remained symptomatic. A TOE was arranged. On a further acute admission CTPA identified direct communication between the lower SVC and left atrium (picture 2,3).Minimal contrast only passed down the lower SVC into the RA and pulmonary tree. Most contrast directly passed from the SVC into the LA. Minimal contrast passed through the pulmonary tree explaining the perfusion study and CTPA results. TOE showed a residual ASD with left to right flow. Injecting agitated saline from antecubital fossa showed only a small amount of flow from SVC to RA but predominantly directly to the LA. Further catheterisation confirmed the fistula suggesting that SVC had been stitched inadvertently at the time of ASD repair and that the SVC communicated with the LA. Surgical repair is planned.

Discussion

This is a unique case of a iatrogenic SVC to LA shunt, although there are several case reports of either left SVC or Right SVC shunting to LA ^1,2,3,4 . The first case was reported in a 52-year-old black male in 1978. Presence of left SVC is rare in the normal population (0.03%) reaching 11% in patients with congenital heart disease. This anomaly results from failure of obliteration of the left anterior cardinal vein during foetal development ⁵. Most of the patients present with paradoxical embolism in early adulthood however many patients with this anomaly present at later stages with SOB and chest pains and dizziness ⁶ . Patients with congenital malformations often present with clubbing and cyanosis. Spiral CT allows evaluation of the course and drainage of the Left SVC if the contrast medium is injected into the left cubital or forearm veins. Furthermore, multiplanar and three-dimensional reconstructions from the spiral CT data set can help not only radiologists but also clinicians and surgeons in therapeutic planning ¹. With CTPA it is good opacification of the pulmonary vessels that allows the dectection of pulmonary emboli. Despite good technique with optimal use of contrast and timing methods occasionally pulmonary opacification remains poor. It is increasingly recognised that this may be due to structural abnormalities with shunting. The poor opacification on this patient`s initial CTPA was due to the SVC to left atrial fistula but this was not recognised at the time. MRI can visualise many congenital heart anomalies as well as venous anomalies like persistant left SVC and anomalous pulmonary venous connection ^7,8 .

References

[1] Gerber TC, Kuzo RS. Persistent left superior vena cava demonstrated with multislice spiral computed tomography. Circulation 2002 Apr 9;105(14):e79. (PMID: 11940557)

[2] Rosenkranz S et al. Anomalous drainage of the right superior vena cava into the left atrium in a 61-year-old woman. Int J Cardiol. 1998 May 15;64(3):285-91. (PMID: 9672410)

[3] Erol I et al. Brain Abscess Associated with Isolated Left Superior Vena Cava Draining into the Left Atrium in the Absence of Coronary Sinus and Atrial Septal Defect. Cardiovasc Intervent Radiol. 2005 Dec 13. (PMID: 16362465)

[4] Pretorius PM et al. Right-sided superior vena cava draining into left atrium in a patient with persistent left-sided superior vena cava. Radiology. 2004 Sep;232(3):730-4. (PMID: 15333794)

[5] Minniti S, Visentini S, Procacci C. Congenital anomalies of the venae cavae: embryological origin, imaging features and report of three new variants. Eur Radiol 2002;12:2040-55. (PMID: 12136323)

[6] Ezekowitz MD et al. Isolated drainage of the superior vena cava into the left atrium in a 52-year-old man: a rare congenital malformation in the adult presenting with cyanosis, polycythemia, and an unsuccessful lung scan. Circulation. 1978 Oct;58(4):751-6. (PMID: 688585)

[7] Higgins CB et al. Magnetic resonance imaging of the heart: a review of the experience in 172 subjects.
Radiology. 1985 Jun;155(3):671-9. (PMID: 3159039)

[8] Sarodia BD, Stoller JK. Persistent left superior vena cava: case report and literature review.
Respir Care. 2000 Apr;45(4):411-6. (PMID: 10780037)

Case information

URL:	https://www.eurorad.org/case/4614
DOI:	10.1594/EURORAD/CASE.4614
ISSN:	1563-4086