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Double-orifice mitral valve causing left ventricular outflow tract obstruction: a hitherto unreported entity

Published online by Cambridge University Press:  30 September 2025

Ishita GargOpen the ORCID record for Ishita Garg[Opens in a new window],
Sreeja PavithranOpen the ORCID record for Sreeja Pavithran[Opens in a new window] and
Sivakumar KothandamOpen the ORCID record for Sivakumar Kothandam[Opens in a new window]
Ishita Garg
Affiliation:
Department of Paediatric Cardiology, Institute of Cardio Vascular Diseases, The Madras Medical Mission, Chennai, India
Sreeja Pavithran*
Affiliation:
Department of Paediatric Cardiology, Institute of Cardio Vascular Diseases, The Madras Medical Mission, Chennai, India
Sivakumar Kothandam
Affiliation:
Department of Paediatric Cardiology, Institute of Cardio Vascular Diseases, The Madras Medical Mission, Chennai, India
*
Corresponding author: Sreeja Pavithran; Email: sreejapavithran@yahoo.com
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Abstract

We report the first documented case of isolated double-orifice mitral valve causing significant left ventricular outflow tract obstruction in an infant. Echocardiography revealed a complete bridge-type double-orifice mitral valve with aberrant chordal insertion into the interventricular septum, producing severe left ventricular outflow tract obstruction. This rare presentation underscores the importance of meticulous echocardiographic assessment for accurate diagnosis and surgical planning.

Keywords

Double-orifice mitral valveleft ventricular outflow obstructioncongenital mitral anomaly

Information

Type
Case Report
Information
Cardiology in the Young , Volume 35 , Issue 10 , October 2025, pp. 2178 - 2180
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Copyright
© The Author(s), 2025. Published by Cambridge University Press

Introduction

Double-orifice mitral valve is a rare congenital malformation characterised by the presence of two distinct openings in the mitral valve, separated by a fibrous bridge. Reference Baño-Rodrigo, Van Praagh, Trowitzsch and Van Praagh1,Reference Trowitzsch, Bano-Rodrigo, Burger, Colan and Sanders2 First described by Greenfield in 1876, double-orifice mitral valve accounts for approximately 1% of CHDs. Reference Trowitzsch, Bano-Rodrigo, Burger, Colan and Sanders2 It typically presents as an incidental finding during evaluation for associated anomalies, such as atrioventricular septal defects, ventricular septal defects, subaortic stenosis, coarctation, bicuspid aortic valve, or Shone’s complex. Reference Warnes and Somerville3,Reference Fernandez Gasso, Jimenez Lopez-Guarch, Garcia Robles and Solis4 Most double-orifice mitral valves are haemodynamically insignificant; when symptomatic, they usually cause mitral regurgitation or mitral stenosis. Reference Baño-Rodrigo, Van Praagh, Trowitzsch and Van Praagh1,Reference Zalzstein, Hamilton, Zucker, Levitas and Gross5

While double-orifice mitral valve has been reported alongside left-sided obstructive lesions, Reference Zalzstein, Hamilton, Zucker, Levitas and Gross5 a direct causation of left ventricular outflow tract obstruction solely by a double-orifice mitral valve is hitherto unreported. We report a unique case where isolated double-orifice mitral valve was responsible for significant left ventricular outflow tract obstruction early in infancy.

Case report

An 11-month-old asymptomatic female infant presented to us with a diagnosis of left ventricular outflow tract obstruction which was detected incidentally on day 3 of life during evaluation of a murmur. Clinical examination revealed mild cardiomegaly, normal heart sounds, and a grade 3/6 harsh ejection systolic murmur at the left sternal border. Chest X-ray showed mild cardiomegaly and features of mild pulmonary venous hypertension. Electrocardiogram (ECG) showed left ventricular hypertrophy.

Transthoracic echocardiography revealed a double-orifice mitral valve with two distinct openings, separated by a fibrous bridge. Both the mitral orifices showed laminar flows with no gradient (Figure 1, Video 1). There was mild mitral regurgitation from both the orifices. The smaller, anterior orifice was directed towards the left ventricular outflow tract, and the chordopapillary apparatus of this orifice was partially inserted across the left ventricular outflow tract onto the interventricular septum. There was significant flow acceleration at the point of insertion of the chordopapillary apparatus into the left ventricular outflow tract (Video 1). Continuous wave doppler revealed a peak and mean gradient of 109 and 60 mm of Hg indicating severe left ventricular outflow tract obstruction (Figure 2). Concentric left ventricular hypertrophy was noted, and the left ventricular systolic function was normal with an ejection fraction of 65%. There were no other intracardiac defects, and aortic arch was normal.

Figure 1.

2D image and colour interrogation of the mitral valve in apical four-chamber view showing double-orifice of the mitral valve with laminar inflows.

Figure 2.

Apical four-chamber view showing severe subvalvar left ventricular outflow tract obstruction caused by chordal insertions of the smaller mitral orifice.

A diagnosis of isolated double-orifice mitral valve causing left ventricular outflow tract obstruction was made, and parents were counselled for an elective surgical repair. However, the patient was subsequently lost to follow-up.

Discussion

Double-orifice mitral valve is a structural anomaly often associated with complex CHDs. Isolated double-orifice mitral valve is relatively rare. Reference Baño-Rodrigo, Van Praagh, Trowitzsch and Van Praagh1,Reference Trowitzsch, Bano-Rodrigo, Burger, Colan and Sanders2,Reference Zalzstein, Hamilton, Zucker, Levitas and Gross5 Associated anomalies such as atrioventricular septal defects, ventricular septal defects, subaortic stenosis, coarctation, and Shone’s complex have been well documented. While double-orifice mitral valve has been previously described with left-sided obstructive lesions, Reference Zalzstein, Hamilton, Zucker, Levitas and Gross5 the obstruction typically arose from discrete subaortic membranes or muscular narrowing rather than from the mitral valve complex itself. Reference Warnes and Somerville3

The embryologic basis of double-orifice mitral valve involves abnormal fusion of the endocardial cushions, resulting in duplication of the mitral valve orifice. Reference Liu, Ren, Ma and Yang6 Anomalies in the tensor apparatus, including aberrant chordal insertion and accessory papillary muscles play a central role in the pathophysiology. Reference Baño-Rodrigo, Van Praagh, Trowitzsch and Van Praagh1 Trowitzsch E et al. classified double-orifice mitral valve morphologically as complete bridge type in which a fibrous bridge divided the atrioventricular orifice completely into equal or unequal parts, incomplete bridge type in which a small strand of tissue connected the anterior and posterior leaflets at the leaflet edge level and hole type in which an additional orifice with subvalvular apparatus occurred in the posterior commissure of the mitral valve. Zalzstein et al. classified double-orifice mitral valve into groups based on functional impact: normal, insufficiency, stenosis, or combined lesions. Reference Zalzstein, Hamilton, Zucker, Levitas and Gross5

In the largest reported cases series of double-orifice mitral valve published by Zalzstein et al, they found that of the 46 children aged 2 days to 16 years, obstructive left-sided lesions were present in 19 patients in the form of aortic coarctation (12 patients), subaortic stenosis (6 patients), and Shone’s complex in 1 patient.

In the present case, we report a complete bridge-type double-orifice mitral valve where the insertion of chordopapillary apparatus of the smaller orifice onto the IVS likely altered the outflow geometry, creating a fixed component of left ventricular outflow tract obstruction. Double-orifice mitral valve as the aetiology of left ventricular outflow tract obstruction has not yet been reported in literature.

This case uniquely highlights double-orifice mitral valve as the sole cause of left ventricular outflow tract obstruction, emphasising the variability and clinical significance of the subvalvular anatomy in such patients.

Modern echocardiographic techniques, especially three-dimensional imaging, improve the visualisation of complex mitral anatomy in greater detail. Reference Liu, Ren, Ma and Yang6 However, we could not obtain optimal three-dimensional images in this young infant due to the lack of a dedicated paediatric 3D echocardiography probe. Recognition of double-orifice mitral valve as the aetiological basis of left ventricular outflow tract obstruction is critical, as it often involves complex mitral valve repair or mitral valve replacement which requires precise planning based on the age and clinical status of the patient.

Conclusion

We describe an extremely rare presentation of isolated double-orifice mitral valve causing significant left ventricular outflow tract obstruction in early infancy. This adds on to the various functional abnormalities described in association with double-orifice mitral valve. Awareness of this association can facilitate precise diagnosis and appropriate surgical repair involving the mitral valve, thereby improving patient outcomes.

Financial support

Nil.

Competing interests

Nil.

Ethical standards

The authors certify that they have obtained all appropriate patient consent forms. The patient’s guardians have consented to the reporting of clinical information with the understanding that anonymity will be maintained.

References

Baño-Rodrigo, A, Van Praagh, S, Trowitzsch, E, Van Praagh, R. Double-orifice mitral valve: a study of 27 postmortem cases with developmental, diagnostic and surgical considerations. Am J Cardiol 1988; 61 :152–160. DOI: 10.1016/0002-9149(88)91322-7.CrossRefGoogle ScholarPubMed
Trowitzsch, E, Bano-Rodrigo, A, Burger, BM, Colan, SD, Sanders, SP. Two-dimensional echocardiographic findings in double orifice mitral valve. J Am Coll Cardiol 1985; 6 :383–387. DOI: 10.1016/S0735-1097(85)80176-5.CrossRefGoogle ScholarPubMed
Warnes, C, Somerville, J. Double mitral valve orifice in atrioventricular defects. Heart 1983; 49 :59–64. DOI: 10.1136/hrt.49.1.59.CrossRefGoogle ScholarPubMed
Fernandez Gasso, L, Jimenez Lopez-Guarch, C, Garcia Robles, JA, Solis, J. Double-orifice mitral valve associated with multivalvular involvement: a new entity? Eur Heart J 2020; 41 :2818–2818. DOI: 10.1093/eurheartj/ehaa240.CrossRefGoogle ScholarPubMed
Zalzstein, E, Hamilton, R, Zucker, N, Levitas, A, Gross, GJ. Presentation, natural history, and outcome in children and adolescents with double orifice mitral valve. Am J Cardiol 2004; 93 :1067–1069. DOI: 10.1016/j.amjcard.2004.01.015.CrossRefGoogle ScholarPubMed
Liu, S, Ren, W, Ma, C, Yang, J. Congenital Double-Orifice mitral valve in asymptomatic patients: comprehensive assessment by three-dimensional echocardiography. Int Heart J 2018; 59 :213–215. DOI: 10.1536/ihj.17-033.CrossRefGoogle Scholar
Figure 0

Figure 1.2D image and colour interrogation of the mitral valve in apical four-chamber view showing double-orifice of the mitral valve with laminar inflows.

Figure 1

Figure 2.Apical four-chamber view showing severe subvalvar left ventricular outflow tract obstruction caused by chordal insertions of the smaller mitral orifice.