A comparison of echocardiographic and electron beam computed tomographic assessment of aortic valve area in patients with valvular aortic stenosis

The purpose of this study was to compare electron beam computed tomography (EBT) with transthoracic echocardiography (TTE) in determining aortic valve area (AVA). Thirty patients (9 females, 21 males) underwent a contrast-enhanced EBT scan (e-Speed, GE, San Francisco, CA, USA) and TTE within 17 ± 12 days. In end-inspiratory breath hold, a prospectively ecg-triggered scan was acquired with a beam speed of 50–100 ms, a collimation of 2 × 1.5 mm and an increment of 3.0 mm. The AVA was measured with planimetry. A complete TTE study was performed in all patients, and the AVA was computed using the continuity equation. There was close correlation between AVA measured with EBT and AVA assessed with TTE (r = 0.60, P < 0.01). The AVA measured with EBT was 0.51 ± 0.46 cm² larger than the AVA calculated with TTE measurements. EBT appeared to be a valuable non-invasive method to measure the AVA. EBT measures the anatomical AVA, while with TTE the functional AVA is calculated, which explains the difference in results between the methods.     

Aortic valves stenosis and regurgitation: assessment with dual source computed tomography

To prospectively evaluate diagnostic accuracy of dual source computed tomography (DSCT) for evaluation of aortic stenosis (AS) and aortic regurgitation (AR) with transthoracic echocardiography (TTE) as reference. We evaluated a total of 79 patients who underwent both DSCT and TTE, 40 with aortic valve disease as assessed by TTE, and 39 matched controls. Maximum aortic valve area (AVA) in systole was planimetrically measured with DSCT, and measurements were compared with TTE, as well as maximum regurgitant orifice area (ROA) in diastole. Dimensions of the aortic root and left ventricular parameters were compared. DSCT correctly identified 30 patients with AS [sensitivity 91%, specificity 100%, positive predictive value (PPV) 100%, and negative predictive value (NPV) 94%], and 32 patients with AR (sensitivity 94%, specificity 98%, PPV 97%, and NPV 96%). A significant correlation was observed between CT planimetric size of aortic valves area and TTE (r = 0.79; P < 0.01). Bland-Altman plot demonstrates a good intermodality agreement between DSCT and TTE with a slight overestimation of AVA by DSCT (+0.14 cm²). A significant correlation was observed between CT planimetric size of ROA (0.49 cm² ± 0.40) and TTE classification of mild, moderate and severe AR (r = 0.79; P < 0.01). With receiver operating characterisitic curve analysis, discrimination between degrees of AR with DSCT was not very accurate within cutoff ROAs. A significant correlation was observed between methods in dimensions of aortic annulus (r = 0.87, P < 0.01), sinus of Valsalva (r = 0.91, P < 0.01), and ascending aorta (r = 0.92, P < 0.01), and in end-systolic volume (r = 0.82, P< 0.01), end-diastolic volume (r = 0.87, P < 0.01) and ejection fraction (r = 0.86, P < 0.01). DSCT can provide a simultaneous and accurate evaluation of the AVA, left ventricular ejection fraction and aortic root dimensions in patients with AS or AR, but measurement of ROA is not very accurate to differentiate severity of AR. DSCT can achieve an exhaustive and comprehensive preoperative assessment of patients with AS and AR.     

Aortic valve area assessed with 320-detector computed tomography: comparison with transthoracic echocardiography

To evaluate the diagnostic accuracy of aortic valve area (AVA) assessment with 320-detector Computed Tomography (MDCT) compared to transthoracic echocardiography (TTE) in a population with mild to severe aortic valve stenosis. AVA was estimated in 169 patients by planimetry on MDCT images (AVA_MDCT) and by the continuity equation with TTE (AVA_TTE). To generate a reference AVA (AVA_REF) we used the stroke volume from MDCT divided by the velocity time integral from CW Doppler by TTE (according to the continuity equation: stroke volume in LVOT = stroke volume passing the aortic valve). AVA_REF was used as the reference to compare both measures against, since it bypasses the assumption of LVOT being circular in the continuity equation and the potential placement error of PW Doppler in the LVOT. The mean (±SD) age of the patients was 71 (±9) years, 113 (67 %) were males. Mean AVA_TTE was 0.93 (±0.33) cm², mean AVA_MDCT was 0.99 (±0.36) cm² and mean AVA_REF was 1.00 (±0.39) cm². The mean difference between AVA_TTE and AVA_MDCT was ?0.06 cm², p = 0.001, mean difference between AVA_TTE and AVA_REF was ?0.06 cm², p < 0.001, and mean difference between AVA_MDCT and AVA_REF was ?0.01 cm², p = 0.60. Calcification of the aortic valve quantified by Agatston score, significantly decreased the correlation between AVA_MDCT and AVA_REF, (r low Agatston = 0.90, r high Agatston = 0.57). MDCT measured AVA is slightly larger than AVA measured by TTE (0.06 cm²). The accuracy and precision errors on AVA measurements are comparable for MDCT and TTE. Valvular calcification may primarily affect the accuracy of AVA_MDCT.     

Preoperative quantification of aortic valve stenosis: comparison of 64-slice computed tomography with transesophageal and transthoracic echocardiography and size of implanted prosthesis

Precise measurements of aortic complex diameters are essential for preoperative examinations of patients with aortic stenosis (AS) scheduled for aortic valve (AV) replacement. We aimed to prospectively compare the accuracy of transthoracic echocardiography (TTE), transoesophageal echocardiography (TEE) and multi-slice computed tomography (MSCT) measurements of the AV complex and to analyze the role of the multi-modality aortic annulus diameter (AAd) assessment in the selection of the optimal prosthesis to be implanted in patients surgically treated for degenerative AS. 20 patients (F/M: 3/17; age: 69?±?6.5?years) with severe degenerative AS were enrolled into the study. TTE, TEE and MSCT including AV calcium score (AVCS) assessment were performed in all patients. The values of AAd obtained in the long AV complex axis (TTE, TEE, MSCT) and in multiplanar perpendicular imaging (MSCT) were compared to the size of implanted prosthesis. The mean AAd was 24?±?3.6?mm using TTE, 26?±?4.2?mm using TEE, and 26.9?±?3.2 in MSCT (P?=?0.04 vs. TTE). The mean diameter of the left ventricle out-flow tract in TTE (19.9?±?2.7?mm) and TEE (19.5?±?2.7?mm) were smaller than in MSCT (24.9?±?3.3?mm, P?<?0.001 for both). The mean size of implanted prosthesis (22.2?±?2.3?mm) was significantly smaller than the mean AAd measured by TTE (P?=?0.0039), TEE (P?=?0.0004), and MSCT (P?<?0.0001). The implanted prosthesis size correlated significantly to the AAd: r?=?0.603, P?=?0.005 for TTE, r?=?0.592, P?=?0.006 for TEE, and r?=?0.791, P?<?0.001 for MSCT. Obesity and extensive valve calcification (AV calcium score????3177Ag.U.) were identified as potent factors that caused a deterioration of both TTE and MSCT performance. The accuracy of AAd measurements in TEE was only limited by AV calcification. In multivariate regression analysis the mean value of the minimum and maximum AAd obtained in MSCT-multiplanar perpendicular imaging was an independent factor (r?=?0.802, P?<?0.0001) predicting the size of implanted prosthesis. In patients with AS echocardiography remains the main diagnostics tool in clinical practice. MSCT as a 3-dimentional modality allows for accurate measurement of entire AV complex and facilitates optimal matching of prosthesis size.     

Central aortic valve coaptation area during diastole as seen by 64-multidetector computed tomography (MDCT)

As multiple new procedures now require better visualization of the aortic valve, we sought to better define the central aortic valve coaptation area seen during diastole on multi-detector row cardiac computed tomography (MDCT). 64-MDCT images of 384 symptomatic consecutive patients referred for coronary artery disease evaluation were included in the study. Planimetric measurements of this area were performed on cross-sectional views of the aortic valve at 75% phase of the cardiac cycle. Planimetric measurement of central regurgitation orifice area (ROA) seen in patients with aortic regurgitation and Hounsfield units of the central aortic valve coaptation area were performed. Mean area of the central aortic valve coaptation area was 5.34 ± 5.19 mm² and Hounsfield units in this area were 123.69 ± 31.31 HU. The aortic valve coaptation area (mm²) measurement in patients without AR was: 4.90 ± 0.17 and in patients with AR: 10.53 ± 0.26 (P = <0.05). On Bland–Altman analysis a very good correlation between central aortic valve coaptation area and central ROA was found (r = 0.80, P = <0.001). Central aortic valve coaptation area is a central area present at the coaptation of nodules of arantius of aortic cusps during diastole; it is incompetent and increased in size in patients with aortic regurgitation.     

Evaluation of aortic valve stenosis using cardiovascular magnetic resonance: comparison of an original semiautomated analysis of phase-contrast cardiovascular magnetic resonance with Doppler echocardiography

Background- Accurate quantification of aortic valve stenosis (AVS) is needed for relevant management decisions. However, transthoracic Doppler echocardiography (TTE) remains inconclusive in a significant number of patients. Previous studies demonstrated the usefulness of phase-contrast cardiovascular magnetic resonance (PC-CMR) in noninvasive AVS evaluation. We hypothesized that semiautomated analysis of aortic hemodynamics from PC-CMR might provide reproducible and accurate evaluation of aortic valve area (AVA), aortic velocities, and gradients in agreement with TTE. Methods and Results- We studied 53 AVS patients (AVA(TTE)=0.87±0.44 cm(2)) and 21 controls (AVA(TTE)=2.96±0.59 cm(2)) who had TTE and PC-CMR of aortic valve and left ventricular outflow tract on the same day. PC-CMR data analysis included left ventricular outflow tract and aortic valve segmentation, and extraction of velocities, gradients, and flow rates. Three AVA measures were performed: AVA(CMR1) based on Hakki formula, AVA(CMR2) based on continuity equation, AVA(CMR3) simplified continuity equation=left ventricular outflow tract peak flow rate/aortic peak velocity. Our analysis was reproducible, as reflected by low interoperator variability (<4.56±4.40%). Comparison of PC-CMR and TTE aortic peak velocities and mean gradients resulted in good agreement (r=0.92 with mean bias=-29±62 cm/s and r=0.86 with mean bias=-12±15 mm Hg, respectively). Although good agreement was found between TTE and continuity equation-based CMR-AVA (r>0.94 and mean bias=-0.01±0.38 cm(2) for AVA(CMR2), -0.09±0.28 cm(2) for AVA(CMR3)), AVA(CMR1) values were lower than AVA(TTE) especially for higher AVA (mean bias=-0.45±0.52 cm(2)). Besides, ability of PC-CMR to detect severe AVS, defined by TTE, provided the best results for continuity equation-based methods (accuracy >94%). Conclusions- Our PC-CMR semiautomated AVS evaluation provided reproducible measurements that accurately detected severe AVS and were in good agreement with TTE.     

Correlation of aortic valve area obtained by the velocity-encoded phase contrast continuity method to direct planimetry using cardiovascular magnetic resonance.

BACKGROUND: Aortic stenosis (AS) is the most common valvular heart disease resulting in surgical intervention. Transthoracic echocardiography (TTE) utilizing the continuity equation is commonly used to determine aortic valve area (AVA). However, sometimes TTE can be limited by poor acoustic windows, heavy valvular calcification, or eccentric jet morphology. Cardiovascular magnetic resonance (CMR) provides an alternative non-invasive method for the evaluation of AVA using direct planimetry. Prior studies have shown good correlation between CMR and other modalities, such as TTE, TEE, and cardiac catheterization. CMR can also assess AVA by using the continuity equation employing velocity-encoded phase contrast (VEPC) imaging. We sought to assess whether velocity-encoded phase-contrast MRI can provide an alternate means of quantifying AVA by CMR. METHODS: Twenty-two consecutive AS patients were imaged with CMR. AVA was determined by VEPC imaging and by direct planimetry. RESULTS: Mean AVA by planimetry was 1.05+/-0.41 cm2 and 1.00+/-0.4 cm2 by VEPC, with a strong correlation (R2=0.86, p<0.0001) between the two methods. The mean difference of AVA was 0.05+/-0.15 (95% CI=[0.02-0.08]), and the limits of agreement were -0.26 to 0.36 cm2. The mean difference between 2 observers for planimetry was 0.030+/-0.07 (95% CI=[0.02-0.04]) with limits of agreement of -0.11 to 0.16 cm2 and for VEPC was 0.008+/-0.085 (95% CI=[-0.01-0.026]) with limits of agreement of -0.16 to 0.18 cm2. CONCLUSIONS: VEPC CMR is an alternative method to direct planimetry for accurately determining AVA. Both techniques can be easily incorporated into a single CMR exam to increase the confidence of AVA determination utilizing cardiac magnetic resonance imaging.     

Aortic valve stenotic area calculation from phase contrast cardiovascular magnetic resonance: the importance of short echo time

Background

Cardiovascular magnetic resonance (CMR) can potentially quantify aortic valve area (AVA) in aortic stenosis (AS) using a single-slice phase contrast (PC) acquisition at valve level: AVA = aortic flow/aortic velocity-time integral (VTI). However, CMR has been shown to underestimate aortic flow in turbulent high velocity jets, due to intra-voxel dephasing. This study investigated the effect of decreasing intra-voxel dephasing by reducing the echo time (TE) on AVA estimates in patients with AS.

Method

15 patients with moderate or severe AS, were studied with three different TEs (2.8 ms/2.0 ms/1.5 ms), in the main pulmonary artery (MPA), left ventricular outflow tract (LVOT) and 0 cm/1 cm/2.5 cm above the aortic valve (AoV). PC estimates of stroke volume (SV) were compared with CMR left ventricular SV measurements and PC peak velocity, VTI and AVA were compared with Doppler echocardiography. CMR estimates of AVA obtained by direct planimetry from cine acquisitions were also compared with the echoAVA.

Results

With a TE of 2.8 ms, the mean PC SV was similar to the ventricular SV at the MPA, LVOT and AoV_{0 cm} (by Bland-Altman analysis bias ± 1.96 SD, 1.3 ± 20.2 mL/-6.8 ± 21.9 mL/6.5 ± 50.7 mL respectively), but was significantly lower at AoV₁ and AoV_2.5 (-29.3 ± 31.2 mL/-21.1 ± 35.7 mL). PC peak velocity and VTI underestimated Doppler echo estimates by approximately 10% with only moderate agreement. Shortening the TE from 2.8 to 1.5 msec improved the agreement between ventricular SV and PC SV at AoV_{0 cm} (6.5 ± 50.7 mL vs 1.5 ± 37.9 mL respectively) but did not satisfactorily improve the PC SV estimate at AoV_{1 cm} and AoV_{2.5 cm}. Agreement of CMR AVA with echoAVA was improved at TE 1.5 ms (0.00 ± 0.39 cm²) versus TE 2.8 (0.11 ± 0.81 cm²). The CMR method which agreed best with echoAVA was direct planimetry (-0.03 cm² ± 0.24 cm²).

Conclusion

Agreement of CMR AVA at the aortic valve level with echo AVA improves with a reduced TE of 1.5 ms. However, flow measurements in the aorta (AoV 1 and 2.5) are underestimated and 95% limits of agreement remain large. Further improvements or novel, more robust techniques are needed in the CMR PC technique in the assessment of AS severity in patients with moderate to severe aortic stenosis.     

Feasibility of a single-beat prospective ECG-gated cardiac CT for comprehensive evaluation of aortic valve disease using a 256-detector row wide-volume CT scanner: an initial experience

The aim of our study was to investigate the feasibility of single-beat prospective electrocardiogram (ECG)-gated cardiac computed tomography (CT) using a 256-detector row wide-volume CT scanner for functional and anatomical evaluation of the aortic valve (AV) and coronary arteries in patients with AV disease. A total of 50 patients who underwent cardiac CT scan with a wide-volume 256-detector row CT scanner for the evaluation of AV and aorta were retrospectively enrolled. Cardiac CT was performed using the prospective ECG-gated acquisition mode, and AV image quality was analyzed using a four-point grading system. Severity of aortic stenosis (AS) and aortic regurgitation (AR) were assessed by CT and correlated to that assessed by transthoracic echocardiography (TTE) based on kappa statistics (κ). Estimated radiation exposure was assessed. Among 50 patients, 44 underwent cardiac CT with single-beat acquisition. The median image quality score of AV was 3.0 on the systolic phase and 4.0 on the diastolic phase. Severity of AS and AR by CT showed moderate agreement with TTE. The mean effective radiation dose was 3.75?±?1.43 mSv for CT angiography. Using 256-detector row wide-volume CT, the single-beat cardiac CT is feasible for evaluation of AV disease and the coronary arteries, with acceptable image quality and a low radiation dose of 3.75 mSv.     

Cardiovascular magnetic resonance for the assessment of patients undergoing transcatheter aortic valve implantation: a pilot study

Background

Before trans-catheter aortic valve implantation (TAVI), assessment of cardiac function and accurate measurement of the aortic root are key to determine the correct size and type of the prosthesis. The aim of this study was to compare cardiovascular magnetic resonance (CMR) and trans-thoracic echocardiography (TTE) for the assessment of aortic valve measurements and left ventricular function in high-risk elderly patients submitted to TAVI.

Methods

Consecutive patients with severe aortic stenosis and contraindications for surgical aortic valve replacement were screened from April 2009 to January 2011 and imaged with TTE and CMR.

Results

Patients who underwent both TTE and CMR (n = 49) had a mean age of 80.8 ± 4.8 years and a mean logistic EuroSCORE of 14.9 ± 9.3%. There was a good correlation between TTE and CMR in terms of annulus size (R² = 0.48, p < 0.001), left ventricular outflow tract (LVOT) diameter (R² = 0.62, p < 0.001) and left ventricular ejection fraction (LVEF) (R² = 0.47, p < 0.001) and a moderate correlation in terms of aortic valve area (AVA) (R² = 0.24, p < 0.001). CMR generally tended to report larger values than TTE for all measurements. The Bland-Altman test indicated that the 95% limits of agreement between TTE and CMR ranged from -5.6 mm to + 1.0 mm for annulus size, from -0.45 mm to + 0.25 mm for LVOT, from -0.45 mm² to + 0.25 mm² for AVA and from -29.2% to 13.2% for LVEF.

Conclusions

In elderly patients candidates to TAVI, CMR represents a viable complement to transthoracic echocardiography.     

Imaging‐based predictors of permanent pacemaker implantation after transcatheter aortic valve replacement

1 Background

Cardiac conduction abnormalities requiring permanent pacemaker (PPM) implantation are major complications of transcatheter aortic valve replacement (TAVR). We aimed to investigate whether the relationship between prosthetic valve size and cardiac‐gated computed tomography (CT)‐based aortic root complex measurements can aid in recognizing patients at risk for PPM implantation post‐TAVR.

2 Methods

We included 83 of 114 consecutive patients who underwent TAVR with the Edwards Sapien valve (Edwards Lifesciences, Irving, CA, USA) at our institution. We excluded patients with preexisting PPM, patients who required conversion to an open surgical procedure, and patients without CT data. We assessed the significance of various potential predictors of PPM placement post‐TAVR.

3 Results

Following TAVR, eight patients (9.6%) required PPM. Prosthetic valve to sinus of Valsalva (SOV) index was significantly higher in those patients requiring a PPM post‐TAVR (84.1 ± 9.3 vs 76.8 ± 7.1, P  =  0.009).

4 Conclusions

The prosthetic valve size to diameter of SOV index was identified as a novel predictor of PPM implantation after TAVR.     

A hybrid approach for quantification of aortic valve stenosis using cardiac magnetic resonance imaging and echocardiography.

BACKGROUND: Doppler-derived calculation of aortic valve area (AVA) using the continuity equation can be difficult at times, e.g. due to poor acoustic windows, heavy calcification of the aortic valve, or significant flow acceleration in the left ventricular outflow tract. The aim of this study was to compare AVA as assessed by means of transthoracic echocardiography (TTE) with a hybrid approach, where the Doppler-derived numerator in the continuity equation was replaced by cardiovascular magnetic resonance (CMR) determination of stroke volume. METHODS: Twenty consecutive patients admitted for evaluation of aortic stenosis underwent transthoracic echocardiography and CMR determination of stroke volume within a time period of 3 weeks. Additionally, continuous-wave Doppler spectra of the aortic valve were acquired immediately after the CMR examination. RESULTS: There was no statistically significant difference for mean AVA between the two methods (0.88 +/- 0.23 cm2 by the standard continuity equation versus 0.86 +/- 0.23 cm2 by the hybrid approach, p = 0.55; r = 0.73, p < 0.01). The mean difference was 0.02 cm2 and the limits of agreement were -0.32 to 0.36. Only 2 patients were classified differently by the two methods. Intraobserver and interobserver variability and reproducibility were superior for the hybrid approach. CONCLUSION: The hybrid method for determination of AVA is an excellent alternative to the standard approach by TTE.     

Hemodynamic stability of valve area, valve resistance, and stroke work loss in aortic stenosis: a comparative analysis.

BACKGROUND: Although aortic valve area (AVA) has provided the standard index for assessing aortic stenosis severity, valve resistance and percent left ventricular stroke work (%LVSW) loss have been proposed as alternative flow independent indices of stenosis severity that may provide a more stable measure under diverse hemodynamic conditions. In 30 patients with moderate or severe aortic stenosis (AVA < or = 1.2 cm(2)), Doppler echocardiography indices of AVA, valve resistance, and %LVSW loss were measured at multiple transvalvular flow rates during dobutamine infusions (0-10 microg/kg/min) to compare their hemodynamic stability. RESULTS: From baseline to maximum dobutamine dose in the 30 patients, transvalvular flow rate increased 43% and resulted in a 42% increase in mean transvalvular pressure gradient, a 15% increase in Doppler AVA, and a 26% increase in %LVSW loss. Group mean valve resistance did not change for the total cohort. For individual patients, AVA and %LVSW loss demonstrated a linear relationship with transvalvular flow (median r = 0.74 and 0.84, respectively). In contrast, both flow-mediated increases and decreases in valve resistance were observed in individual patients, resulting in the apparent stability of the group mean valve resistance in the total cohort. For individual patients, Doppler AVA and valve resistance demonstrated comparable stability in response to changes in hemodynamic conditions and were significantly more stable than mean transvalvular pressure gradient and %LVSW loss. CONCLUSION: Doppler AVA and valve resistance provide stenotic indices of equivalent hemodynamic stability. However, transvalvular flow has a predictable directional effect on AVA and an unpredictable directional effect on valve resistance, potentially limiting valve resistance as a measure of hemodynamic severity.     

Demonstration of left ventricular outflow tract eccentricity by 64-slice multi-detector CT

Background Newer three-dimensional imaging technologies provide insight into cardiac shape and geometry from views previously unobtainable. Standard formulae like the continuity equation (CE) that rely on inherent assumptions about left ventricular outflow tract (LVOT) shape may need to be revisited. In the CE, small changes in LVOT diameter may significantly change calculated aortic valve area (AVA). Using 64-slice Multi-detector CT (MDCT), we performed LVOT planimetry to obviate the need for any geometric assumptions. Methods 64-slice MDCT was performed in 30 consecutive patients. The diameter-derived LVOT area (ALVOT_diam) was calculated from a view analogous to the 2D echo parasternal long axis. Direct planimetry of the LVOT (ALVOT_plan) was performed just beneath the aortic valve in a plane perpendicular to the LVOT long axis. Further, assuming an ellipsoid outflow tract shape, LVOT area (ALVOT_ellip) was calculated using πab from the long and short diameters of the planimetered LVOT view. Eccentricity index (EI) was estimated by subtracting the ratio of shortest and longest LVOT diameters from one. Results ALVOT_diam always measured smaller than ALVOT_plan (mean 3.7 ± 1.2 cm² vs. 4.1 ± 1.3 cm², respectively). The median EI was 0.18 (95% CI = 0.16–0.2; P = 0.0001). ALVOT_ellip more closely agreed with ALVOT_plan (correlation = 0.96; P < 0.0001) than did ALVOT_diam (correlation = 0.87; P < 0.0001). Conclusion Using MDCT, the LVOT was shown to be elliptical in most patients. Applying the CE which assumes roundness of the LVOT consistently underestimated the LVOT area which may affect estimated AVA. Planimetry of the LVOT utilizing three-dimensional imaging modalities such as 3-D echocardiography, MRI, or MDCT may render a more precise AVA.     

超声心动图在经导管主动脉瓣置换术前评估与术后随访中的应用价值

目的探讨超声心动图在评估经导管主动脉瓣置换（TAVR）术前与术后心脏结构和功能改变中的应用价值。 方法回顾性选取2014年9月至2019年7月在复旦大学附属中山医院心内科行TAVR的重度主动脉瓣狭窄（SAS）患者47例。所有患者均于术前及术后6个月行经胸超声心动图检查并记录常规超声心动图参数和主动脉瓣相关参数,包括左心室收缩末期内径（LVESD）、左心室舒张末期内径（LVEDD）、室间隔厚度（IVST）、后壁厚度（PWT）、肺动脉收缩压（PASP）、主动脉瓣最大跨瓣压差（AVPGmax）、主动脉瓣平均跨瓣压差（AVPGmean）、主动脉瓣有效瓣口面积（AVA）、左心室射血分数（LVEF）、主动脉根部内径（AORD）、左心房内径（LAD）,分析TAVR术前与术后的超声心动图参数变化。 结果与术前相比,术后47例患者的LVESD、IVST、PWT、PASP、AVPGmax、AVPGmean均明显减小,差异均有统计学意义（P均＜0.05）;AVA和LVEF均明显变大,差异均有统计学意义（P均＜0.05）。术后合并二尖瓣反流中度及以上或三尖瓣反流中度及以上的患者较术前明显减少（8例vs 3例,7例vs 2例）。 结论TAVR可纠正主动脉瓣狭窄,改善患者心功能。超声心动图相关参数有助于TAVR术后人工瓣膜及患者心脏结构功能的随访评估。     

经导管主动脉瓣置换术前实时三维经食管超声自动测量主动脉瓣环径

目的 探讨经导管主动脉瓣置入术（TAVR）中应用实时三维经食管超声心动图（3D-TEE）自动测量主动脉瓣环的可行性与准确性。方法 对21例拟接受TAVR患者于术前分别采用3D-TEE和多排CT（MDCT）测量主动脉瓣环面积、周长、最大径和最小径。对比3D-TEE测值与MDCT测值间的差异及相关性,记录3D-TEE自动测量主动脉瓣环参数所需的时间。结果 3D-TEE所测主动脉瓣环面积为（445.74±62.60）mm²,周长为（76.16±5.30）mm,最大径为（26.29±1.97）mm,最小径为（21.40±1.68）mm,MDCT测值分别为（456.85±75.70）mm²、（77.17±5.90）mm、（26.76±2.83）mm、（20.98±1.76）mm。MDCT与3D-TEE所测主动脉瓣环面积、周长、最大径及最小径差异均无统计学意义（P均>0.05）。3D-TEE与MDCT所测主动脉瓣环面积、周长、最大径、最小径均呈高度相关（r=0.89、0.91、0.85、0.79,P均<0.01）。采用3D-TEE自动测量主动脉瓣相关径线所需时间为（1.54±0.21）min。结论 3D-TEE自动测量主动脉瓣环能准确、快速获得主动脉瓣环相关径线,可作为替代MDCT的影像学方法。     

A simplified continuity equation approach to the quantification of stenotic bicuspid aortic valves using velocity-encoded cardiovascular magnetic resonance.

OBJECTIVE: We aimed to compare velocity-encoded cine cardiac magnetic resonance (CMR) with an established echocardiographic method for noninvasive measurement of aortic valve area (AVA) using the continuity equation. METHODS AND RESULTS: Twenty consecutive young adults with stenotic bicuspid aortic valves were examined with CMR and transthoracic echocardiography (TTE). CMR AVA was calculated by the continuity equation, dividing stroke volume by the aortic velocity-time integral (VTIAorta), the stroke volume measured both by ventricular volume analysis and by phase contrast velocity mapping at 4 levels (1 subvalvar and 3 supravalvar). Stroke volumes measured at all levels correlated well with those from volumetric analysis. The CMR AVAs calculated using volumetric analysis and VTIAorta from jet velocity mapping correlated and agreed well with TTE AVA measurements (R2 = 0.83). When CMR AVA was calculated more rapidly using volume flow and VTIAorta both measured from the same trans-jet velocity acquisition, R2 was 0.74, with a bias and limits of agreement of 0.02 (-0.44, 0.47) cm2. CONCLUSIONS: Continuity equation calculation of the AVA using CMR velocity mapping, with or without ventricular volumetric measurement, correlated and agreed well with the comparable and widely accepted TTE approach.     

超声心动图评价牛心包置换单叶主动脉瓣治疗主动脉瓣关闭不全

目的 应用经胸和经食管超声心动图评价牛心包置换单叶主动脉瓣治疗主动脉瓣关闭不全的效果.方法 应用经胸和经食管超声心动图对25例牛心包置换单叶主动脉瓣治疗主动脉瓣关闭不全患者行术前、体外循环停机后术中检测和术后3～6个月随访,判定瓣膜结构、病变和反流程度,同一切面相同时相测量手术前后左房、左室内径.结果 25例患者术前经胸超声检测反流与停机后术中反流程度差异有统计学意义(P＜0.001);术中停机后经食管超声与术后3～6个月经胸超声检测反流程度比较差异无统计学意义(P＞0.1);术后3～6个月左房内径[(3.19±0.90)cm]、左室内径[(4.72±1.19)cm]较术前[左房(3.80±1.37)em,左室(5.75±1.32)em]明显回缩,手术前后测值差异有统计学意义(P＜0.001).结论 牛心包置换单叶主动脉瓣治疗主动脉瓣关闭不全近期疗效较好,远期效果尚待观察.     

Coronary flow reserve: measurement with transthoracic Doppler echocardiography is reproducible and comparable with positron emission tomography

Detection of early vascular changes indicated by lowered coronary flow reserve (CFR) would allow early treatment and prevention of atherosclerosis. The purpose of this study was to test whether it is possible to reproducibly measure CFR with transthoracic Doppler echocardiography (TTE) in healthy volunteers. We measured CFR using dipyridamole infusion in ten healthy male volunteers with two methods: TTE and positron emission tomography (PET) with oxygen‐15‐labelled water (group A). However, CFR was assessed twice with TTE in eight healthy male volunteers (group B) to study the reproducibility of this method. We compared CFRs obtained using TTE flow measurements in the left anterior descending coronary artery (LAD) and PET flow measurements in the corresponding myocardial area. Coronary flow in LAD could be measured in all subjects using TTE. By TTE, an average CFR based on peak diastolic flow velocity (PDV) was 2·72 ± 1·16, mean diastolic flow velocity (MDV) 2·56 ± 1·06 and velocity time integral (VTI) 1·87 ± 0·49. The results were reproducible in two repeated TTE studies (coefficient of variation in MDV 6·1 ± 4·3%, n=8). By PET, CFR was 2·52 ± 0·84. CFR assessed by TTE correlated closely with that measured by PET (MDV r=0·942, P<0·001; PDV r=0·912, P<0·002 and VTI r=0·888, P<0·006) and intraclass correlation was 0·929 (MDV) and tolerance limits for differences of CFRs was ?0·78 to 0·72. We show that CFR measured by TTE has an excellent correlation with CFR measured by PET. We also found that TTE measurements of CFR were highly reproducible.     

超声心动图用于心尖入路经导管主动脉瓣植入术

目的 评价超声心动图用于心尖入路经导管主动脉瓣植入术(TAVI)的价值.方法 纳入23例接受J-Valve TAVI的主动脉瓣疾病患者,根据主要疾病,将其中20例非重度主动脉瓣狭窄(AS)合并中度以上主动脉瓣反流(AR)者分为AS组(n=10)及AR组(n=10).术前行经胸超声心动图(TTE),术中全程以经食管超声心...