Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2005 Aug;91(8):1030-5.
doi: 10.1136/hrt.2003.027839. Epub 2005 Mar 10.

Hypoxaemia associated with an enlarged aortic root: a new syndrome?

J-C Eicher  1 , P Bonniaud, N Baudouin, A Petit, G Bertaux, E Donal, J F Piéchaud, M David, P Louis, J E Wolf
Affiliations

Hypoxaemia associated with an enlarged aortic root: a new syndrome?

J-C Eicher et al. Heart. 2005 Aug.

Abstract

Objective: To assess the mechanisms through which an enlarged aortic root may facilitate right to left shunting through a patent foramen ovale.

Patients: 19 patients with the platypnoea-orthodeoxia syndrome (POS) were compared with 30 control patients without platypnoea.

Interventions: Multiplane transoesophageal echocardiography.

Main outcome measures: The aortic root diameter, atrial septal dimension behind the aortic root, and amplitude of the phasic oscillation of the septum were measured. Four groups of patients were compared: 12 platypnoeic patients with a dilated aortic root (POS-D), 7 platypnoeic patients with a normal aortic root (POS-N), 15 control patients with a dilated aortic root (CONT-D), and 15 control patients with a normal aortic root (CONT-N).

Results: In POS-D and CONT-D patients, the apparent atrial septal dimension was 16.3 (2.7) mm and 17.4 (5.9) mm respectively, compared with 24.4 (5.2) mm in POS-N patients and 25 (4) mm in CONT-N (p < 0.005). Furthermore, the amplitude of septal oscillation was 14.7 (2.5) mm in the POS-D group versus 5.8 (2.4) mm in CONT-N (p < 0.001) compared with 23.3 (3) mm in seven patients with an atrial septal aneurysm (p < 0.001).

Conclusion: Patients with an enlarged aorta have an apparently smaller dimension and increased mobility of the atrial septum. These findings appear to result from compression by the aortic root and decreased septal tautness. Consequently, a "spinnaker effect" with the inferior vena caval flow may take place, opening the foramen ovale and leading to sustained right to left shunting.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Transoesophageal echocardiographic measurements. (A) Patient with a dilated aortic root (AoR). (B) Patient with a normal AoR. LA, left atrium; RA, right atrium.
Figure 2
Figure 2
Apparent atrial septal (AS) dimension as measured behind the AoR in the four groups of patients. CONT, control patients; D, dilated aortic root; N, normal aortic root; POS, platypnoea-orthodeoxia syndrome. *p < 0.05 v POS-N; †p < 0.05 v CONT-N.
Figure 3
Figure 3
AS oscillation amplitude in patients in the CONT-N, CONT-D, and POS-D groups without an atrial septal aneurysm (ASA) and with an ASA. *p < 0.005 v controls; †p < 0.005 v ASA.
Figure 4
Figure 4
Transoesophageal echocardiography during a transcatheter closure procedure in a patient with a dilated AoR. Patent foramen ovale opens exactly opposite the inferior vena cava (IVC), as shown by the guidewire coming from the vein and crossing the defect directly (left). Colour Doppler imaging shows that flow coming from the IVC is perpendicular to the atrial septal plane (arrow) and lifts the flap valve of the fossa ovalis intermittently, promoting right to left shunting (right). The bulging AoR probably also contributes to drive flow against the septum. Ao, aorta.
See this image and copyright information in PMC

References

    1. Schnabel TG, Ratto O, Kirby CK, et al. Postural cyanosis and angina pectoris following pneumonectomy: relief by closure of an interatrial septal defect. J Thorac Surg 1956;32:246–50. - PubMed
    1. Mercho N, Stoller JK, White RD, et al. Right-to-left interatrial shunt causing platypnea after pneumonectomy. Chest 1994;105:931–3. - PubMed
    1. Strunk BL, Cheitlin MD, Stulbarg MS, et al. Right-to-left interatrial shunting through a patent foramen ovale despite normal intracardiac pressures. Am J Cardiol 1987;60:413–5. - PubMed
    1. Schneider B, Hofmann T, Justen MH, et al. Chiari’s network: normal anatomic variant or risk factor for arterial embolic events? J Am Coll Cardiol 1995;26:203–10. - PubMed
    1. Thomas JD, Tabakin BS, Ittleman FP. Atrial septal defect with right to left shunt despite normal pulmonary artery pressure. J Am Coll Cardiol 1987;9:221–4. - PubMed

MeSH terms