Supravalvular Ring Mitral Stenosis Workup
- Author: Michael D Pettersen, MD; Chief Editor: Howard S Weber, MD, FSCAI more...
No specific laboratory blood tests are required for diagnosis of supravalvar mitral ring.
In cases of isolated supravalvar mitral ring, the electrocardiogram demonstrates left atrial enlargement, right ventricular hypertrophy, and right atrial enlargement in proportion to the degree of obstruction.
Additional defects influence the electrocardiogram accordingly.
Imaging studies are essential to define the anatomy of the ring and mitral valve, to assess the severity of obstruction, and to identify any associated defect before undertaking surgical treatment. Several examples of imaging studies are shown in the videos below.
Left atrial enlargement, the most common abnormality on chest radiographs in patients with mitral obstruction, is diagnosed on the basis of straightening of the left cardiac border (mitralization), widening of the tracheal carina, and elevation of the left bronchus. In older children, the enlarged left atrium may be seen as a double opacity near the right cardiac border.
The left atrium tends to enlarge in a posterior direction.
Prominent upper-lobe pulmonary veins, increased interstitial markings, and Kerley lines indicate pulmonary venous hypertension. In severe cases, alveolar edema produces a hazy appearance in the hilar regions of both lung fields.
The pulmonary trunk and its branches become dilated with the rise in pulmonary arterial pressure. The cardiac contour reflects right ventricular hypertrophy.
Two-dimensional echocardiography with Doppler imaging is the most important tool for the diagnosis and detailed assessment of patients with supravalvar mitral ring. It depicts the lesion and helps in quantifying the severity of the obstruction.
Detailed scanning of the mitral valve and left atrium should be performed using multiple transthoracic views and by paying particular attention to all components of the mitral valve apparatus. Use parasternal, apical, and subcostal views to visualize the mitral inflow region.
Using this technique allows visualization of the supravalvar mitral ring and definition of its exact position, size, and extent as well as assessment of the relationship of the ring to the mitral valve leaflets.
On occasion, a thin membrane may so closely adhere to the valve leaflets that it is difficult to visualize on 2-dimensional echocardiography. With an adherent membrane, the movements of mitral-valve leaflets may be impaired. The presence of supramitral flow acceleration identified with color Doppler imaging may help identify such a membrane.
The mitral-valve chordae and papillary muscles should be carefully inspected for any associated abnormalities. Associated defects such as subaortic stenosis, ventricular septal defect (VSD), and coarctation of the aorta should be evaluated.
The pulmonary artery, right ventricle, and right atrium may be enlarged in patients with pulmonary arterial hypertension.
Use M-mode echocardiography of the pulmonary valve, which often shows such signs of pulmonary hypertension as an abbreviated A wave, midsystolic closure, and systolic flutter of pulmonary leaflets.
Real-time 3-dimensional echocardiography permits comprehensive assessment of the mitral valve and may compliment 2-dimensional transthoracic echocardiography.
Doppler interrogation and color-flow mapping reveal the pattern of flow through the mitral valve, diagnose the presence and severity of obstruction, and demonstrate additional areas of abnormal flow in valvar or subvalvar mitral regions. The characteristic finding is turbulent flow with increased velocity across the supravalvar mitral ring into the mitral valve.
The severity of mitral obstruction may be assessed by measuring the mean velocity of diastolic flow through the mitral valve. The mean diastolic velocity and the pressure half-time (time for the peak diastolic velocity to decrease to half its initial value) are well correlated with the severity of obstruction.
The peak velocity of the tricuspid regurgitant jet in the right atrium can be measured to estimate the systolic right ventricular pressure.
Continuous wave Doppler interrogation is shown in the image below.
In children, transesophageal echocardiography is generally not necessary to assess a supravalvar mitral ring with obstruction because adequate information can be obtained from transthoracic windows.
In adults, transesophageal study can provide additional clear views to inspect all components of the supravalvar mitral ring and mitral valve.
Thrombi in the left atrium may be detected.
Intraoperative transesophageal echocardiography is useful for patients of all ages to assess adequacy of repair in the operating room.
Cardiac catheterization is not necessary if echocardiography provides all of the necessary anatomic and hemodynamic data in patients with supravalvar mitral ring. However, it can provide additional information about the severity of mitral obstruction, especially in the presence of other associated congenital heart disease (CHD).
Proximal left atrial pressure and pulmonary venous pressure are both elevated. A diastolic pressure difference can be demonstrated between the left atrium and the left ventricle (LV). Because entry into the left atrium may be difficult and because transseptal puncture may be required, the pressure recorded in the pulmonary artery wedge position is usually a reliable indicator of left atrial pressure. Simultaneous recording of pressures in the pulmonary artery wedge position and the LV is shown in the image below.
Pulmonary artery pressure is elevated in chronic mitral obstruction. Associated shunts and other obstructive lesions are also identified and quantified during cardiac catheterization.
With the availability of high-quality 2-dimensional and Doppler echocardiography, cardiac angiography has a limited role in the assessment of patients with supravalvar mitral ring. Echocardiography is superior to angiography in defining the anatomic and functional abnormality.
Left atrial angiography in the caudally angulated right anterior oblique view and the 4-chamber view may demonstrate the supravalvar mitral ring. However, a closely adherent ring may be difficult to visualize and differentiate from mitral valvar stenosis. The left atrium and appendage are enlarged, and clearance of contrast material from the left atrium into the LV is delayed.
An LV angiogram provides additional anatomic information about the mitral valve, ventricular septum, LV outflow tract, and aortic arch.
Akgullu C, Erdogan E. Adult patient with Shone's syndrome and patent ductus arteriosus: a case report. Turk Kardiyol Dern Ars. 2012 Jun. 40(4):350-3. [Medline].
Alvares S, Melo AS, Antunes M. Divided left atrium associated with supravalvar mitral ring. Cardiol Young. 1999 Jul. 9(4):423-6. [Medline].
Hertwig C, Haas NA, Habash S, Hanslik A, Kececioglu D, Sandica E, et al. The "Polar Light Sign" is a useful tool to detect discrete membranous supravalvular mitral stenosis. Cardiol Young. 2014 Jan 28. 1-5. [Medline].
Kutty S, Colen TM, Smallhorn JF. Three-dimensional echocardiography in the assessment of congenital mitral valve disease. J Am Soc Echocardiogr. 2014 Feb. 27(2):142-54. [Medline].
Banerjee A, Kohl T, Silverman NH. Echocardiographic evaluation of congenital mitral valve anomalies in children. Am J Cardiol. 1995 Dec 15. 76(17):1284-91. [Medline].
Brown JW, Ruzmetov M, Rodefeld MD, Turrentine MW. Surgical strategies and outcomes in patients with supra-annular mitral ring: a single-institution experience. Eur J Cardiothorac Surg. 2010 Nov. 38(5):556-60. [Medline].
Delmo Walter EM, Van Praagh R, Miera O, Hetzer R. Repair of left ventricular inflow tract lesions in Shone's anomaly: valve growth and long-term outcome. Ann Thorac Surg. 2013 Mar. 95(3):948-55. [Medline].
del Nido PJ, Baird C. Congenital mitral valve stenosis: anatomic variants and surgical reconstruction. Semin Thorac Cardiovasc Surg Pediatr Card Surg Annu. 2012. 15(1):69-74. [Medline].
Selamet Tierney ES, Pigula FA, Berul CI, Lock JE, del Nido PJ, McElhinney DB. Mitral valve replacement in infants and children 5 years of age or younger: evolution in practice and outcome over three decades with a focus on supra-annular prosthesis implantation. J Thorac Cardiovasc Surg. 2008 Oct. 136(4):954-61, 961.e1-3. [Medline].
Kanter KR, Kogon BE, Kirshbom PM. Supra-annular mitral valve replacement in children. Ann Thorac Surg. 2011 Dec. 92(6):2221-7; discussion 2227-9. [Medline].
Bolling SF, Iannettoni MD, Dick M 2nd, Rosenthal A, Bove EL. Shone's anomaly: operative results and late outcome. Ann Thorac Surg. 1990 Jun. 49(6):887-93. [Medline].
Brauner RA, Laks H, Drinkwater DC Jr, Scholl F, McCaffery S. Multiple left heart obstructions (Shone's anomaly) with mitral valve involvement: long-term surgical outcome. Ann Thorac Surg. 1997 Sep. 64(3):721-9. [Medline].
Brown JW, Ruzmetov M, Vijay P, et al. Operative results and outcomes in children with Shone's anomaly. Ann Thorac Surg. 2005 Apr. 79(4):1358-65. [Medline].
Chen GZ, Huang GY, Liang XC, et al. Methodological study on real-time three-dimensional echo-cardiography and its application in the diagnosis of complex congenital heart disease. Chin Med J (Engl). 2006 Jul 20. 119(14):1190-4. [Medline].
Collison SP, Kaushal SK, Dagar KS, et al. Supramitral ring: good prognosis in a subset of patients with congenital mitral stenosis. Ann Thorac Surg. 2006 Mar. 81(3):997-1001. [Medline].
Delmo Walter EM, Komoda T, Siniawski H, Miera O, Van Praagh R, Hetzer R. Long-term surgical outcome of mitral valve repair in infants and children with Shone's anomaly. Eur J Cardiothorac Surg. 2012 Sep 1. [Medline].
Glaser J, Yakirevich V, Vidne BA. Preoperative echographic diagnosis of supravalvular stenosing ring of the left atrium. Am Heart J. 1984 Jul. 108(1):169-71. [Medline].
Huhta JC, Edwards WD, Danielson GK. Supravalvular mitral ridge containing the dominant left circumflex coronary artery. J Thorac Cardiovasc Surg. 1981 Apr. 81(4):577-9. [Medline].
Ikemba CM, Eidem BW, Fraley JK, et al. Mitral valve morphology and morbidity/mortality in Shone's complex. Am J Cardiol. 2005 Feb 15. 95(4):541-3. [Medline].
Ma XJ, Huang GY, Liang XC, Liu XQ, Jia B. Atypical Shone's complex diagnosed by echocardiography. Pediatr Cardiol. 2011 Apr. 32(4):442-8. [Medline].
Malhotra SP, Lacour-Gayet F, Campbell DN, et al. Outcomes of reparative and transplantation strategies for multilevel left heart obstructions with mitral stenosis. Ann Thorac Surg. 2008 Oct. 86(4):1305-9; discussion 1310. [Medline].
Martin RP, Qureshi SA, Radley-Smith R. Acquired supravalvar membranous stenosis of the left atrioventricular valve. Br Heart J. 1987 Aug. 58(2):176-8. [Medline].
McElhinney DB, Sherwood MC, Keane JF, et al. Current management of severe congenital mitral stenosis: outcomes of transcatheter and surgical therapy in 108 infants and children. Circulation. 2005 Aug 2. 112(5):707-14. [Medline].
Moraes F, Lapa C, Ventura C, et al. Supravalvular congenital mitral stenosis. Arq Bras Cardiol. 2002 Jul. 79(1):79-84. [Medline].
Mychaskiw G, Sachdev V, Braden DA, et al. Supramitral ring: an unusual cause of congenital mitral stenosis. Case series and review. J Cardiovasc Surg (Torino). 2002 Apr. 43(2):199-202. [Medline].
Oglietti J, Reul GJ Jr, Leachman RD, et al. Supravalvular stenosing ring of the left atrium. Ann Thorac Surg. 1976 May. 21(5):421-4. [Medline].
Roche KJ, Genieser NB, Ambrosino MM, Henry GL. MR findings in Shone's complex of left heart obstructive lesions. Pediatr Radiol. 1998 Nov. 28(11):841-5. [Medline].
Shone JD, Sellers RD, Anderson RC, et al. The developmental complex of "parachute mitral valve," supravalvular ring of left atrium, subaortic stenosis, and coarctation of aorta. Am J Cardiol. 1963 Jun. 11:714-25. [Medline].
Smilari P, Romeo MG, Sciacca P, et al. Cerebral venous sinuses thrombosis in an infant with supramitral obstructive membrane associated with partial anomalous pulmonary venous return [in Italian]. Minerva Pediatr. 2005 Apr. 57(2):111-6. [Medline].
Snider RA, Roge CL, Schiller NB, et al. Congenital left ventricular inflow obstruction evaluated by two-dimensional echocardiography. Circulation. 1972. 61:848-852. [Medline].
Sullivan ID, Robinson PJ, de Leval M, et al. Membranous supravalvular mitral stenosis: a treatable form of congenital heart disease. J Am Coll Cardiol. 1986 Jul. 8(1):159-64. [Medline].
Tanaka K, Makuuchi H, Naruse Y, et al. Mitral stenosis due to fibrous tissue overgrowth after mitral valve repair. J Cardiovasc Surg (Torino). 2003 Feb. 44(1):59-60. [Medline].
Thilenius OG, Vitullo D, Bharati S, et al. Endocardial cushion defect associated with cor triatriatum sinistrum or supravalve mitral ring. Am J Cardiol. 1979 Dec. 44(7):1339-43. [Medline].
Toscano A, Pasquini L, Iacobelli R, et al. Congenital supravalvar mitral ring: an underestimated anomaly. J Thorac Cardiovasc Surg. 2009 Mar. 137(3):538-42. [Medline].
Tulloh RM, Bull C, Elliott MJ, Sullivan ID. Supravalvar mitral stenosis: risk factors for recurrence or death after resection. Br Heart J. 1995 Feb. 73(2):164-8. [Medline].
Vaideeswar P, Baldi MM, Warghade S. An analysis of 24 autopsied cases with supramitral rings. Cardiol Young. 2009 Feb. 19(1):70-5. [Medline].
[Guideline] Wilson W, Taubert KA, Gewitz M, et al. Prevention of infective endocarditis: guidelines from the American Heart Association: a guideline from the American Heart Association Rheumatic Fever, Endocarditis, and Kawasaki Disease Committee, Council on Cardiovascular Disease in the Young, and the Council on Clinical Cardiology, Council on Cardiovascular Surgery and Anesthesia, and the Quality of Care and Outcomes Research Interdisciplinary Working Group. Circulation. 2007 Oct 9. 116(15):1736-54. [Medline].