European Heart Journal Advance Access originally published online on February 9, 2008
European Heart Journal 2008 29(20):2526-2535; doi:10.1093/eurheartj/ehn022
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Assessing aortic valve area in aortic stenosis by continuity equation: a novel approach using real-time three-dimensional echocardiography
1 Cardiac Ultrasound Laboratory, Division of Cardiology, Blake 256, Massachusetts General Hospital, Harvard Medical School, 55 Fruit Street, Boston, MA 02114, USA
2 Cardiac Department, National University Hospital, Singapore
3 Biostatistics Unit, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
Received 5 July 2007; revised 17 December 2007; accepted 10 January 2008; online publish-ahead-of-print 9 February 2008.
* Corresponding author. Tel: +1 617 726 0995, Fax: +1 617 726 8383, Email: jhung{at}partners.org.
Aims: Two-dimensional echocardiographic (2DE) continuity-equation derived aortic valve area (AVA) in aortic stenosis (AS) relies on non-simultaneous measurement of left ventricular outflow tract (LVOT) velocity and geometric assumptions of LVOT area, which can amplify error, especially in upper septal hypertrophy (USH). We hypothesized that real-time three-dimensional echocardiography (RT3DE) can improve accuracy of AVA by directly measuring LVOT stroke volume (SV) in one window.
Methods and results: RT3DE colour Doppler and 2DE were acquired in 68 AS patients (74 ± 12 yrs) prospectively. SV was derived from flow obtained from a sampling curve placed orthogonal to LVOT (Tomtec Imaging). Agreement between continuity-equation derived AVA by RT3DE (AVA3D-SV) and 2DE (AVA2D) and predictors of discrepancies were analysed. Validation of LVOT SV was performed by aortic flow probe in a sheep model with balloon inflation of septum to mimic USH. There was only modest correlation between AVA2D and AVA3D-SV (r = 0.71, difference 0.11 ± 0.23 cm2). The degree of USH was significantly associated with difference in AVA calculation (r = 0.4, P = 0.005). In experimentally distorted LVOT geometry in sheep, RT3DE correlated better with flow probe assessment (r = 0.96, P < 0.001) than 2DE (r = 0.71, P = 0.006).
Conclusion: RT3DE colour Doppler-derived LVOT SV in the calculation of AVA by continuity equation is more accurate than 2D, including in situations such as USH, common in the elderly, which modify LVOT geometry.
Key Words: Aortic stenosis • Real-time three-dimensional echocardiography • Colour Doppler • Valvular heart disease • Continuity equation
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  G. de la Morena, D. Saura, M. J. Oliva, F. Soria, J. Gonzalez, M. Garcia, V. Moreno, J. C. Bonaque, and M. Valdes Real-time three-dimensional transoesophageal echocardiography in the assessment of aortic valve stenosis Eur J Echocardiogr, October 4, 2009; (2009) jep154v1. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. Schoenhagen, E. M. Tuzcu, S. R. Kapadia, M. Y. Desai, and L. G. Svensson Three-dimensional imaging of the aortic valve and aortic root with computed tomography: new standards in an era of transcatheter valve repair/implantation Eur. Heart J., September 1, 2009; 30(17): 2079 - 2086. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 F. von Knobelsdorff-Brenkenhoff, A. Rudolph, R. Wassmuth, S. Bohl, E. E. Buschmann, H. Abdel-Aty, R. Dietz, and J. Schulz-Menger Feasibility of Cardiovascular Magnetic Resonance to Assess the Orifice Area of Aortic Bioprostheses Circ Cardiovasc Imaging, September 1, 2009; 2(5): 397 - 404. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. E. Thomas, Z. R. Yousef, and A. G. Fraser A critical comparison of echocardiographic measurements used for optimizing cardiac resynchronization therapy: stroke distance is best Eur J Heart Fail, August 1, 2009; 11(8): 779 - 788. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 V. Mor-Avi, L. Sugeng, and R. M. Lang Real-Time 3-Dimensional Echocardiography: An Integral Component of the Routine Echocardiographic Examination in Adult Patients? Circulation, January 20, 2009; 119(2): 314 - 329. [Full Text] [PDF]
|
|
|
|
 |
|
 B. Jungwirth and G. B. Mackensen Real-Time 3-Dimensional Echocardiography in the Operating Room Seminars in Cardiothoracic and Vascular Anesthesia, December 1, 2008; 12(4): 248 - 264. [Abstract] [PDF]
|
|