Quantitation of aortic valve area in aortic stenosis with multiplane transesophageal echocardiography: Comparison with monoplane transesophageal approach

doi:10.1016/0002-8703(94)90627-0

American Heart Journal

Volume 128, Issue 3, September 1994, Pages 526-532

https://doi.org/10.1016/0002-8703(94)90627-0 Get rights and content

Abstract

The accuracy and reliability of two-dimensional monoplane and multiplane transesophageal echocardiography (TEE) in the quantitation of aortic valve area were compared in 54 patients with aortic stenosis. Fiffy patients had aortic valve area calculated by the continuity equation and transthoracic Doppler echocardiography (TTE); 25 underwent cardiac catheterization. Two-dimensional echocardiograms adequate for quantitation of aortic valve area were obtained in 21 (39%) patients with monoplane TEE and in 51 (94%) with multiplane TEE. The mean aortic valve area determined by both TEE methods did not differ significantly from that derived from TTE and catheterization. The mean difference of aortic valve area measurements between monoplane TEE and TTE was −0.045 ± 0.11 cm²; that between multiplane TEE and TTE was 0.001 ± 0.11 cm². Multiplane TEE provided a better correlation of aortic valve area measurements with either TTE (y = 0.97x + 0.03; r = 0.96; SEE = 0.11 cm²) or catheterization (y = 0.84x + 0.11; r = 0.90; SEE = 0.12 cm²) than the monoplane TEE (y = 0.88x + 0.13; r = 0.83; SEE = 0.15 cm² and y = 0.41x + 0.42; r = 0.81; SEE = 0.15 cm²). Severe aortic stenosis with valve orifice area of ≤ 0.75 cm² during TTE examination was found by multiplane TEE with a sensitivity of 96% and a specificity of 96%. Thus aortic valve area can be directly and reliably measured by two-dimensional multiplane TEE in majority of patients with aortic stenosis.

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Cited by (58)

Three-dimensional imaging of the left ventricular outflow tract: Impact on aortic valve area estimation by the continuity equation
2012, Journal of the American Society of Echocardiography
Measurement of left ventricular outflow tract (LVOT) area for estimation of aortic valve area (AVA) using two-dimensional (2D) transthoracic echocardiography (TTE) and the continuity equation assumes a round LVOT. The aim of this study was to compare measurements of LVOT area and AVA using 2D and three-dimensional (3D) TTE and cardiac computed tomographic angiography (CCTA) in an attempt to improve the accuracy of AVA estimation using TTE.
Fifty patients were prospectively studied, 25 with aortic stenosis and 25 without aortic stenosis (group 1). LVOT area and AVA were estimated using 2D TTE, and LVOT area and diameters were measured using 256-slice CCTA and 3D TTE. AVA was also planimetered using CCTA in midsystole. LVOT area and AVA estimated by 2D TTE were correlated with measurements by 3D TTE and CCTA. Findings from group 1 were then validated in 38 additional patients with aortic stenosis (group 2).
LVOTs were oval in 96% of the patients in group 1, with a mean eccentricity index (diameter 2/diameter 1) of 1.26 ± 0.09 by CCTA. Compared with CCTA, 2D TTE systematically underestimated LVOT area (and therefore AVA) by 17 ± 16%. The correlation between CCTA and 3D TTE LVOT area was only moderate (r = 0.63), because of inadequate 3D transthoracic echocardiographic image quality. Mean AVA was 0.92 ± 0.44 cm² by 2D TTE and 1.14 ± 0.68 cm² by CCTA (P = .0015). After correcting AVA on 2D TTE by a factor of 1.17 (accounting for LVOT area ovality), there was no difference between 2D TTE and CCTA (0.06 ± 26 cm², P = .20, r = 0.86). In group 2, 2D TTE underestimated LVOT area and AVA by 16 ± 11%, similar to group 1, and AVA by TTE was 0.75 ± 0.14 cm² compared with 0.88 ± 0.21 cm² by CCTA (P < .0001). When the correction factor was applied to the group 2 results, the corrected AVA by 2D TTE (×1.17) was 0.87 ± 0.17 cm², similar to AVA by CCTA (P = .70).
Three-dimensional imaging revealed oval LVOTs in most patients, resulting in underestimation of LVOT area and AVA on 2D TTE by 17%. This accounted for the difference in AVA between 2D TTE and CCTA. Current 3D TTE is inadequate to accurately measure LVOT area.
The role of echocardiography in the evaluation and management of aortic stenosis in the older adult
2012, International Journal of Cardiology
Citation Excerpt :
In older adults the prevalence of severely calcified valvular cusps which cause acoustic shadowing and interfere with visualization using 2DTEE in addition to anatomical variations caused by a dilated or obliquely placed aorta is increased [33]. Another limitation faced by 2DTEE is the inability to ensure that the imaging plane is aligned perpendicular to the plane of the orifice [34,35]. Since this depends on the relationship of the probe in the esophagus and the aortic root, which is fixed in a particular individual but variable from one person to another, it is technically difficult to ensure that the imaging plane is parallel to the plane of the orifice.
Aortic stenosis is currently the most predominant valvular pathology in older adults. Signs and symptoms of aortic stenosis in this age-group may be difficult to recognize due to the decreased activity associated with aging and attribution of symptoms to other conditions. Echocardiography can be very helpful in the assessment of valvular structure and real time hemodynamic evaluation as well as in the progression of the disease over time. Unprecedented advances in echocardiography, including real time three-dimensional echocardiography, facilitate a comprehensive assessment of this condition and help in the decision-making process. Recent innovations in the percutaneous treatment of valvular diseases promise a revolution in the treatment of aortic stenosis especially in older adults.
Aortic Stenosis Quantitation
2010, Dynamic Echocardiography
Unanticipated Mild-to-Moderate Aortic Stenosis During Coronary Artery Bypass Graft Surgery: Scope of the Problem and Its Echocardiographic Evaluation
2009, Journal of Cardiothoracic and Vascular Anesthesia
Citation Excerpt :
However, there are limitations to the various echocardiographic techniques used for this purpose of which the echocardiographer should be aware.22 With the introduction of transesophageal echocardiography (TEE), the assessment of AVA by planimetry was found to be a quick and simple method of the assessment of AS severity.23-25 Initial attempts at the delineation of the AVA with planimetry were made by using a monoplane probe and then a multiplane transesophageal echocardiographic probe and showed acceptable correlations with invasive methods.26,27
Direct measurement of left ventricular outflow tract by transthoracic real-time 3D-echocardiography increases accuracy in assessment of aortic valve stenosis
2009, International Journal of Cardiology
Citation Excerpt :
In patients with impaired left ventricular function resulting in decreased validity of pressure gradient measurements, non-invasive determination of the degree of aortic valvular stenosis according to the continuity equation may be superior, especially since planimetric measurement of aortic valvular areas is affected by actual transvalvular flow [24–26]. Transesophageal echocardiography provides a good acoustic window and thus superior image resolution which allows accurate direct measurement in many patients by multiplane [27,28] and three-dimensional approach [29,30]. However, transesophageal approach is also subject to limitations like artifacts arising from severe calcification and the choice of the cut-plane which substantially influences the resulting aortic valvular orifice.
Evaluation of aortic valve stenosis is a major clinical application of echocardiography. The widely employed continuity equation requires determination of the left ventricular outflow tract (LVOT) area. We aimed at testing whether direct area measurement in a volume data set is superior to conventional calculation from the LVOT diameter.
We performed LVOT measurement in 20 normal subjects and 83 patients with moderate to severe aortic stenosis with a transthoracic real-time three-dimensional echocardiography (3D-TTE) technique in two systolic frames. The off-line 3D-evaluation allows full choice of section planes within the acquired volume data set. The aortic valve area was calculated from systolic LVOT areas. These results were compared to area values obtained by M-mode LVOT-diameters (area = π ^⁎ (d / 2)²). In addition, the calculated aortic valve orifices were compared to invasive measurements or direct planimetry in the transthoracic or transesophageal examination.
Two independent observers found a reduction in LVOT area during systole (p < 0.001). Often a more ellipsoid-like shaped LVOT resulted at end-systole which was shown by a reduction (p < 0.001) of the LVOT longitudinal to oblique axis ratio. 3D-TTE determination of aortic valve orifice areas (mean difference: − 0.04 ± 0.09 cm²) showed a lesser deviation from the invasively or planimetrically measured areas than conventionally calculated LVOT areas (mean difference: − 0.1 ± 0.1 cm²) using the continuity equation (p < 0.001).
The tested transthoracic 3D-echocardiography technique offers non-invasive measurement of the LVOT and aortic valve area based on the continuity equation during systole and thus improves accuracy and, additionally, agreement of aortic valvular area determination with invasive and direct measurements.
Aortic Stenosis
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Quantitation of aortic valve area in aortic stenosis with multiplane transesophageal echocardiography: Comparison with monoplane transesophageal approach

Abstract

Am J Cardiol

Am J Cardiol

Am Heart J

Am J Cardiol

Limitations in assessing the severity of aortic stenosis by Doppler gradients

Br Heart J

Noninvasive estimation of valve area in patients with aortic stenosis by Doppler ultrasound and two-dimensional echocardiography

Circulation