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Keywords:

  • accessory mitral valve;
  • color Doppler;
  • color Doppler transesophageal echocardiography;
  • mitral stenosis

Double Orifice Mitral Valve

  1. Top of page
  2. Double Orifice Mitral Valve
  3. References
  4. Supporting Information

A 55-year-old female, presented to our outpatient department with complaints of dyspnea on exertion, NYHA grade II for 7 years, which had progressed to NYHA Grade III in the past 6 months. On examination, long mid-diastolic murmur with loud first heart sound was heard in the apex. ECG (RMS, Panchkula, Haryana, India) showed features of left atrial enlargement and right ventricular hypertrophy. On chest x-ray, there was cardiomegaly and double atrial shadow suggestive of left atrial enlargement with features of pulmonary venous hypertension. An echocardiogram (GE Healthcare, Pittsburgh, PA, USA) done showed severe mitral stenosis with mitral valve fused in the middle to create an appearance of 2 separate valves (complete bridge type) with areas of 0.3 and 0.5 cm2 respectively (Figs. 1 and 2 with movie clips S1 and S2). Two separate turbulent jets were observed across both these stenotic valves with mean gradients of 11 and 10 mmHg (Figs. 3 and 5 with movie clips S3, S5, and S6). No mitral regurgitation was seen and there was no associated congenital anomaly seen on echocardiogram. Severe tricuspid regurgitation with severe pulmonary artery hypertension was observed (right ventricular systolic pressure, 72 mmHg). Due to presence of moderate to severe subvalvular disease (Fig. 4 with movie clip S4), she was sent for mitral valve replacement.

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Figure 1. Two mitral valves with valve areas of 0.3 and 0.5 cm2 respectively in parasternal short-axis view.

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Figure 2. Two mitral valves in apical two-chamber view (left image shown by arrows) and 2 separate jets across the 2 valves (right image shown by arrows).

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Figure 3. The gradient across the medial mitral valve.

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Figure 4. The severe subvalvular disease of the mitral valve apparatus in parasternal long-axis view shown by arrow.

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Figure 5. The 2 separate jets across the 2 valves on transesophageal echocardiogram shown by arrows.

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Double orifice mitral valve, first described by Greenfield in 1876, is a rare congenital anomaly in which the anterior and posterior leaflets of mitral valve fuse to create 2 separate valves with the chordae around each valve attached to only one papillary muscle. Three varieties of double orifice mitral valve have been described by Trowitzch et al.[1]: (1) an incomplete bridge type, in which a small strand of tissue connected the anterior and posterior leaflets at the leaflet edge level; (2) a complete bridge type in which a fibrous bridge divided the atrioventricular orifice completely into equal or unequal parts; and (3) a hole type, in which an additional orifice with subvalvular apparatus occurred in the posterior commissure of the mitral valve. These 3 types could be distinguished by sweeping the transducer in cross-sectional view from the apex toward the base of the heart. Both orifices could be seen throughout the scan in the complete bridge type while in the incomplete bridge type the 2 orifices could be seen only at the level of the papillary muscles. In the hole type, the second orifice was seen at about mid-leaflet level.

This condition is usually associated with other malformations like atrioventricular septal defects, ventricular septal defects, coarctation of aorta, ostium primum and secundum atrial septal defects and hypoplastic left heart syndrome. Abnormality of the tensor apparatus is usually found in most of these patients.[2] Most of these patients do not have extensive thickening of subvalvular apparatus. Our patient had moderate to severe subvalvular disease which combined with the fact that it was an isolated anomaly may point to the rheumatic etiology of this condition as the prevalence of rheumatic heart disease is high in our country. Definitive treatment of this anomaly is surgical valve repair or replacement[4] although there are case reports of balloon mitral valvotomy in cases with incomplete bridge and without having commissural fusion or subvalvular disease[3] on echocardiogram. In these cases, an initial balloon size that is 4 mm less than required was chosen and then stepwise dilatation of the mitral valve was performed. Since there was presence of moderate to severe subvalvular disease in our patient with commissural fusion, we decided to send the patient for mitral valve replacement than to attempt balloon mitral valvotomy.

To conclude, isolated double orifice mitral valve is a rare anomaly that requires careful echocardiographic evaluation to decide whether balloon mitral valvuloplasty or surgery is needed for the patient.

References

  1. Top of page
  2. Double Orifice Mitral Valve
  3. References
  4. Supporting Information
  • 1
    Trowitzch E, Rodrigo AB, Burger BM, et al: Two dimensional echocardiographic findings in double orifice mitral valve. J Am Coll Cardiol 1985;6:383387.
  • 2
    Rodrigo AB, Praagh SV, Trowitzch E, et al: Double orifice mitral valve: A study of 27 post mortem cases with developmental, diagnostic and surgical considerations. Am J Cardiol 1988;61:152160.
  • 3
    Lo PH, Hung JS, Lau KW, et al: Inoue balloon mitral valvuloplasty in double orifice mitral stenosis. J Invasive Cardiol 2003;15:301303.
  • 4
    Dogan OF, Demircin M, Karagoz T: Diagnosis and management of double orifice mitral valve: Three case reports. Heart Surg Forum 2005;8:E236E240.

Supporting Information

  1. Top of page
  2. Double Orifice Mitral Valve
  3. References
  4. Supporting Information
FilenameFormatSizeDescription
echo12381-sup-0001-VID1.avivideo/avi3850KMovie clip S1. Two separate mitral valves in parasternal short-axis view (left side image) with 2 separate turbulent flows across the mitral valves (right side image).
echo12381-sup-0002-VID2.avivideo/avi4386KMovie clip S2. Two separate mitral valves in apical four-chamber views (left side image) with 2 separate turbulent flows across the mitral valves (right side image).
echo12381-sup-0003-VID3.avivideo/avi9199KMovie clip S3. Gradient across the medial stenotic mitral valve.
echo12381-sup-0004-VID4.avivideo/avi3635KMovie clip S4. Severe subvalvular disease of the mitral valves in parasternal long-axis view.
echo12381-sup-0005-VID5.avivideo/avi748KMovie clip S5. Two separate jets across the stenotic mitral valves on transesophageal echocardiogram.
echo12381-sup-0006-VID6.avivideo/avi8013KMovie clip S6. Gradient across the lateral stenotic mitral valve.

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