The value of Doppler echocardiography in the management of patients with valvular heart disease: analysis of one year of clinical practice

Management recommendations based on Doppler echocardiographic examination and cardiac catheterization were compared in a prospective study in 100 consecutive patients who were admitted for evaluation and treatment of suspected valvular heart disease during 1988. Management recommendations were provided independently after both Doppler echocardiography and cardiac catheterization by different and blinded investigators. Criteria for severe (clinically significant) and moderate to mild (insignificant) valvular lesions and management recommendations were agreed on in advance. There was disagreement on the severity of aortic stenosis based on the aortic valve area and maximum instantaneous pressure gradient in 1 of 54 patients, which resulted in differing management recommendations. Mitral stenosis was severe (valve area less than or equal to 1 cm2) at Doppler echocardiography but not at cardiac catheterization in 5 of 14 patients. Because pulmonary artery pressure increase during exercise at cardiac catheterization also suggested severe obstruction, management recommendations were similar. There was a potentially significant disagreement on the severity of aortic regurgitation in 9 of 76 patients and of mitral regurgitation in 14 of 90 patients; however, this did not produce differing management recommendations because with most patients coexistent valvular lesions or an impaired ventricular function mainly determined the ultimate management decision. Although of good quality, Doppler echocardiographic examination was nonconclusive for clinical decision-making in 15% of the study population because of uncertainty about the severity of mitral regurgitation or aortic regurgitation or because of problems in assessing the degree of left ventricular dysfunction in patients with severe regurgitation.(ABSTRACT TRUNCATED AT 250 WORDS)     

Doppler echocardiography. Role in emergency diagnosis of cardiac valve disease

Doppler echocardiography provides crucial information in the evaluation of a patient with suspected significant heart valve dysfunction. Doppler studies can provide quantitative data on the gradients across the stenotic valves and in many cases derive the actual valve area (with use of the pressure half-time method for stenotic atrioventricular valves or the continuity equation for semilunar valves). When combined with two-dimensional echocardiographic studies, Doppler studies may discern the cause of valve dysfunction. In valvular regurgitation, semi-quantitative estimation of the severity of the problem can be obtained by pulsed Doppler flow mapping or color Doppler echocardiography. These methods show great value for rapid evaluation of valve dysfunction in the emergency setting.     

An alternative to standard continuity equation for the calculation of aortic valve area by echocardiography

Calculation of aortic valve area by echocardiography is sometimes technically difficult. We tested a modified continuity equation to help measure valve area in those difficult cases. The studies of 105 patients with aortic stenosis were analyzed retrospectively. We calculated aortic valve area by standard continuity equation and by the modified method where Doppler-derived stroke volume was replaced by the difference between diastolic and systolic volume according to Simpson's biplane method of disks. The correlation between the 2 methods was excellent. For patients with left ventricular outflow tract acceleration, modified continuity equation correlated better than standard continuity equation with invasively measured aortic valve area by Gorlin equation. We conclude that the modified method is accurate and becomes an attractive alternative to the conventional continuity equation especially for patients in whom stroke volume calculation by Doppler may be unreliable for technical reasons.     

Morphologic bases for establishing end-points for early plaque detection and plaque instability

The aim of the present study was to investigate which factors could influence the accuracy of aortic stenosis severity assessment by Doppler echocardiography in an unselected population. Doppler echocardiographic determination of mean transvalvular pressure gradient and aortic valve area by continuity equation was performed in 101 patients before catheterization. According to the catheterization data, aortic stenosis was classified into 2 categories: mild to moderate (orifice area [Gorlin formula] > 0.75 cm², mean transvalvular gradient < 50 mmHg) and severe (orifice area < 0.75 cm², mean transvalvular gradient ≥ 50 mmHg). The influence of eight factors on the absolute difference in aortic valve area and mean transvalvular pressure gradient and on the concordant classification in the same category by both methods was investigated.Results. By multivariate analysis, the absolute difference in aortic valve area by both methods was significantly associated with poor image quality, absolute difference between mean catheterization and Doppler transvalvular gradient and inversely related to body mass index. Absolute difference in mean transvalvular gradients by both methods was significantly associated only with image quality. Poor image quality emerged as the only significant factor influencing the concordant classification between invasive and noninvasive studies according to orifice area (but not according to transvalvular pressure gradient).Conclusion. Echographic image quality significantly influences the accuracy of Doppler echocardiographic determination of aortic valve area and, to a lesser extent, of transvalvular pressure gradient. Therefore, the mere noninvasive approach is not suitable to every consecutive patient with aortic stenosis. Qualifications concerning overall image quality should identify patients most likely to benefit from catheterization.     

Recent developments in aortic stenosis

There have been several recent advances in our understanding of aortic stenosis and in its diagnosis and treatment. Aortic stenosis is now most commonly due to a bicuspid valve. Rheumatic aortic stenosis has become much less common and calcific stenosis of valves in the elderly is a rapidly increasing cause. The prognosis of patients with aortic stenosis can be largely determined by their symptoms, with a mean length of survival of 3 to 5 years for patients with angina, 3 years for patients with syncope, and only 12 to 24 months for patients with heart failure. Virtually all symptomatic patients should be operated on, even those with reduced left ventricular function. The risk of sudden death in asymptomatic adults is low, and thus surgery is generally not needed in these cases. Recently, the noninvasive diagnosis of aortic stenosis has improved dramatically with the advent of two-dimensional and Doppler echocardiography. These techniques provide information on the pressure gradient and can even allow accurate estimates of valve area. Cardiac catheterization is still required, however, to determine the anatomy of the coronary arteries prior to surgery since many patients will have concomitant coronary artery disease. The newest development in the treatment of aortic stenosis is catheter balloon valvuloplasty, which is relatively safe and has shown early promise in reducing the pressure gradient across not increased to the normal range and is significantly less than that following aortic valve replacement. The long-term results of balloon valvuloplasty are still being evaluated.(ABSTRACT TRUNCATED AT 250 WORDS)     

Jet eccentricity: a misleading source of agreement between Doppler/catheter pressure gradients in aortic stenosis.

Characterization of the severity of aortic stenosis relies on accurate measurement of the pressure gradient across the valve and the valve area. Pressure gradients measured by Doppler ultrasound based on the clinical form of the Bernoulli equation often overestimate pressure gradients by catheter as the result of pressure recovery. Doppler techniques measure the velocity of the vena contracta of the stenotic jet. This corresponds to the maximal pressure gradient and the minimal effective valve area. Pressure recovery can be characterized by analysis of the spread of the stenotic jet downstream of the valve as it fills the aorta and should be influenced by the shape of the velocity profile of the decaying jet. In this study, we addressed the hypothesis that the site of complete pressure recovery (the point at which the jet fully expands to the size of the aorta), the effective valve area, and the maximal pressure gradient are affected by jet eccentricity. To accomplish this, we developed a computational model of aortic stenosis that provides detailed velocity and pressure information in the vicinity of the valve. The results show that the width of the eccentric wall jet decreased and maximal velocity increased with greater jet eccentricity. Furthermore, for a constant anatomic area, the effective valve area decreased, the distance to complete pressure recovery increased, and the maximal pressure gradient increased with the degree of eccentricity. Failure to take this into account could fortuitously drive Doppler and catheter measurements toward agreement because the distal pressure sensor will not record the fully recovered pressure. Therefore the pressure gradient across a stenotic valve depends on jet eccentricity. The spread of the wall jet after attachment must be characterized to develop a robust method for the prediction of pressure recovery.     

The value of Doppler echocardiography findings in selecting patients with aortic stenosis for surgical intervention

Doppler echocardiographic and catheter measurements of pressure gradients were compared in 29 patients (61 +/- 11 a) with isolated aortic stenosis. In addition we retrospectively evaluated which easily obtained Doppler echocardiographic parameters might indicate severe aortic stenosis requiring surgery. Catheter-derived peak to peak and mean gradients correlated well with maximum systolic Doppler gradient (r = 0.78, p less than 0.01) and mean Doppler gradient (r = 0.73, p less than 0.01). Using the continuity equation, the aortic valve area was assessed in 14 patients by Doppler echocardiography. A good correlation was found with catheter-determined aortic valve area (r = 0.83, p less than 0.01). Surgical intervention was recommended in 19 patients after left heart catheterisation. Doppler determined maximum transvalvular flow velocity (Vmax.) was greater than 4.5 m/s in 10 patients, all ultimately considered to be surgical candidates. None of the 7 patients with Vmax. less than 3.8 m/s proved to have critical aortic stenosis. In 12 patients Vmax. was between 3.8 and 4.5 m/s. In this group aortic valve replacement was advised in 9 patients after catheterisation. In 5 surgical candidates echocardiography showed reduced left ventricular function (systolic shortening fraction less than 0.27). Hence, the Doppler derived peak flow velocity greater than 4.5 m/s or peak flow greater than 3.8 m/s in the presence of reduced left ventricular function indicate severe aortic stenosis requiring surgery.     

Internal consistency of echocardiographic estimates of the severity of left ventricular outflow obstruction

To determine their internal consistency, M-mode and Doppler echocardiography were used to estimate the gradient across the left ventricular outflow tract during 74 evaluations of 50 infants, children, and young adults with congenital valvular (n = 43), subvalvular (n = 6), and supravalvular (n = 1) aortic stenosis. By M-mode the gradient was estimated from the wall-stress formula (left ventricular pressure = 225 x wall thickness/end-systolic diameter) minus systolic blood pressure determined by sphygmomanometry. Doppler (pulsed or continuous wave) methods utilized the Bernoulli formula (gradient = 4 x V2). There was good agreement between the M-mode and Doppler estimates of outflow gradient in most patients (r = 0.69, standard error of the estimate = 26.9). In 46 of 74 comparisons (62%) the two estimates differed by less than 20 mm Hg, and the estimates placed the patient in the same clinical class (mild, moderate, or severe). In 22 patients undergoing cardiac catheterization, there was only a fair correlation between the M-mode (r = 0.50) and Doppler (r = 0.58) gradients and those obtained at catheterization. Each noninvasive technique yielded major overestimates or underestimates of the gradient in several instances. The M-mode and Doppler techniques for estimating the severity of congenital aortic stenosis are complementary. Their combined use minimizes but does not totally eliminate errors of overestimation or underestimation of outflow gradient.     

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.     

超声心动图评估主动脉瓣置换术后早期并发症的临床应用

主动脉瓣置换术(AVR)是目前治疗有症状的主动脉瓣病变的标准手术。AVR可明显改善主动脉瓣狭窄或反流患者的临床症状及血流动力学,手术效果好,远期生存率高。尽管经导管主动脉瓣置入术(TAVI)也被认可为治疗主动脉瓣病变的有效手段,但目前AVR仍然是最可靠的手术方式。超声心动图是主动脉瓣狭窄或反流最重要的诊断方法,是一种安全可靠的无创检测技术,在术前评估、明确手术指证、选择手术方式、判断预后等方面有重要的价值。AVR术后30d内发生的早期并发症影响患者预后,目前主要依靠超声心动图来检测和诊断。常规超声心动图的应用最为广泛,近年来超声心动图新技术如组织多普勒显像(TDI)、二维或三维斑点追踪显像、负荷超声心动图的应用也得到越来越多的临床医师重视。然而,超声心动图对AVR术后早期并发症的预测价值尚无充分的证据证明。笔者对AVR术后主要早期并发症及超声心动图检测方法进行系统回顾,以期为探究超声心动图指标预测术后早期并发症的价值提供参考。     

Comprehensive Assessment of Aortic Stenosis in the TAVR Era

Purpose of Review

Transcatheter aortic valve replacement (TAVR) has been approved for the treatment of severe aortic stenosis in patients who are prohibitive surgical risk, high surgical risk, and now intermediate surgical risk. This review aims to raise awareness of the role echocardiography in evaluating patients with aortic stenosis for TAVR, in assisting during the procedure for device placement and to identify procedural complications and in assessing follow-up valvular and cardiac function to guide ongoing therapy.

Recent Findings

A comprehensive echocardiogram is an essential part of the evaluation of patients with aortic stenosis. Severe aortic stenosis is present in patients with a peak aortic velocity of >?4 m/s, mean gradient >?40 mmHg, and AVA <?1.0 cm2. In patients with reduced LV systolic function, dobutamine echocardiography may help differentiate patients with true low-gradient aortic stenosis from patients with pseudo-aortic stenosis. Echocardiography is used in conjunction with fluoroscopy to assist with valve placement and is important in identifying procedural complications including paravalvular regurgitation. Follow-up echocardiography is strongly recommended at 30 days following the procedure and then annually to assess valvular function and hemodynamic effects following correction of the aortic stenosis.

Summary

In the TAVR era, echocardiography will play a critical role in the evaluation and treatment of the patient with aortic stenosis.

     

Transesophageal echocardiography assessment of severe ostial left main coronary stenosis.

Doppler echocardiography is commonly used in the assessment of stenotic valvular orifices. We describe the application of transesophageal echocardiography for the detection of a critical ostial left main coronary stenosis. Because preoperative coronary angiography often is not routinely performed in young patients undergoing valve surgery, application of Doppler echocardiography can potentially prevent catastrophic complications, particularly in atypical cases.     

彩色多普勒超声心动图对老年退行性心脏瓣膜病变的诊断价值

目的:研究探索彩色多普勒超声心动图对老年退行性心脏瓣膜病变的影响,并加以讨论。方法:选取2018年7月至2019年7月在本院接受彩色多普勒超声心动图检测的老年退行性心脏瓣膜病体检者973例进行研究讨论,选取年龄 60岁至90岁,评价老年退行性心脏瓣膜病变检出的情况及瓣膜病变伴反流和狭窄情况。结果:男性阳性检出率为21.2%,女性阳性检出率为19.2%,阳性检出率男性稍高于女性;198例阳性患者中,超声显示,119例伴有主动脉瓣反流,占60.1%,4例伴有主动脉瓣狭窄,占2%。结论:若老年退行性心脏瓣膜病患者使用展彩色多普勒超声心动图法进行检测,能对体检者瓣膜的厚度、活动度及回声强弱等有一些帮助治疗的了解,对诊断有重要价值,可以判断疾病严重程度,为治疗方案的确定提供可靠依据。     

经胸和经食管超声心动图诊断主动脉瓣穿孔的价值

目的：探讨经胸超声心动图（TTE）和多平面经食管超声心动图（MTEE）诊断主动脉瓣感染性心内膜炎（AVIE）伴主动脉瓣穿孔（AVP）的价值。方法：对10例经TTE或（和）MTEE诊断的AVIE并发AVP患 超声心动图资料进行分析,将超声特点与手术结果进行对照。结果：TTE或MTEE诊断AVIE并AVP的要点为二维超级心动图显示瓣体的回声连续中继或缺失,彩色多普勒血流显像显示瓣体回声缺失部位穿瓣偏心血流,其特异性为100％,敏感性为90．9％,TTE结合MTEE对AVP的定位、定量诊断有较高的正确性,结论TTE和MTEE检查是早期正确诊断AVIE并发AVP的首选方法,有重要临床应用价值。     

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.     

多平面经食管超声心动图观察主动脉瓣病变

本文对３１例主动脉瓣病变患者进行了多平面经食道超声心动图（ＭＴＥＥ）的研究，其中主动脉瓣狭窄１２例（主动脉瓣二瓣化７例，风湿性３例，退行性病变２例），主动脉瓣关闭不全１９例（风湿性１０例，升主动脉夹层动脉瘤４例，赘生物３例，单纯脱垂２例）。主要从食管中上段的一系列切面观察主动脉瓣的形态结构。ＭＴＥＥ在确定主动脉瓣病变的病因方面明显优于ＴＴＥ。在判断主动脉瓣狭窄和主动脉瓣返流的程度方面ＭＴＥＥ具有重     

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.     

超声心动图评估新型主动脉人工瓣膜Perceval Sorin

目的 探讨超声在新型主动脉人工瓣膜Perceval Sorin临床试验研究中的应用价值.方法 术前、术中、术后7 d和术后1个月,使用经胸超声心动图及经食管超声心动图检查经主动脉瓣及人工瓣膜Perceval Sorin的血流速度曲线,记录最大跨瓣压差和平均压差,彩色多普勒判断主动脉瓣反流程度,术后有无瓣周漏.结果 15例患者术前均患有中-重度主动脉瓣狭窄,Perceval Sorin置换后,主动脉跨瓣平均压差(12.57±1.99)mm Hg(1 mm Hg=0.133 kPa),瓣口面积(1.37±0.28)cm~2.无瓣周漏,1例(1/15)患者术后主动脉瓣口少量反流,余患者术后主动脉瓣口微量反流或未见反流.结论 Perceval Sorin置换手术后,术后主动脉跨瓣压差明显减低,瓣口面积明显增大.超声心动图能及时准确评价治疗效果,提供有价值的信息.     

Doppler echocardiography as a predictor of pregnancy outcome in the presence of aortic stenosis: A case report.

Aortic stenosis in pregnancy can be a life-threatening condition, but fortunately it is rare. In the modern era, careful obstetric and cardiologic monitoring, particularly through echocardiography, have improved fetal and maternal outcomes. However, a test that could predict outcome has not been available for patients with aortic stenosis who seek prepregnancy counseling. We report a case in which exercise Doppler echocardiography was used to predict cardiac function and maximal gradients in a woman with a bicuspid aortic valve who wished to become pregnant.     

Beat-by-beat aortic valve area measurements indicate constant orifice area in aortic stenosis: analysis of Doppler data with varying RR intervals.

Gorlin formula calculation of aortic valve area suggests that orifice area increases in patients with aortic stenosis with rising cardiac output. Evidence that aortic orifice area varies was sought in patients with aortic stenosis by analyzing Doppler data beat by beat versus RR interval in 22 patients with spontaneous RR variability. Stroke volume increased in all patients from minimum to maximum RR interval by 129% +/- 19%. Over the same range of RR intervals, assessment of aortic valve area by (A) simultaneous inner and outer continuous wave Doppler signals, or (B) nonsimultaneous RR-matched pulsed wave Doppler from the left ventricular outflow tract and continuous wave Doppler from the aortic valve failed to suggest an increase in aortic valve area. A positive relationship between aortic valve area and RR interval was not consistently observed with the exception of seven out of eight patients with mild to moderate (pulsed wave Doppler/continuous wave Doppler time velocity integral ratio of 0.3 to 0.7) aortic stenosis (p less than 0.05). Beat-by-beat measurements of aortic valve orifice area using Doppler techniques do not suggest that the aortic stenosis orifice varies over a wide range of RR intervals and stroke volumes.