Quantitative assessment of valvular regurgitations using the pulsed Doppler technique. Approach to the regurgitant lesion

It is now possible with pulsed Doppler to grade the severity of aortic, mitral and tricuspid regurgitations on a quantitative basis. “Indices” were devised, using the measurement of the spatial extent of abnormal Doppler signals.For aortic regurgitation: (1) at the aortic valvular orifice area, by measurement of the regurgitant aortic valvular area and calculation of the valvular regurgitant “index”. (2) In the left ventricle outflow tract, by calculation of an “index” combining information from two echographic (short and long axis) planes.For mitral regurgitation: by calculation of the total regurgitant “index” combining information from examination of the annulus in short axis, and of the left atrium in long axis view.For tricuspid regurgitation: at the tricuspid annulus, by averaging the depth of the reversal wave on two samples recorded using various echographic approaches.A group of patients with aortic (42), mitral (55) and tricuspid (57) regurgitation proven by invasive procedures, was investigated with this procedure using a 3 MHz two dimensional pulsed Doppler echo device. Correlative coefficients between the Doppler grading and that provided by independently performed invasive procedures on a three point scale, ranged between 0.66 and 0.88, with significant differentiation of mean values of indices (P < 0.01 to P < 0.001) for each grade of severity.Success in the Doppler grading of severity of the regurgitations requires (1) a sampling as close as possible to the lesion, and optimally at the very site of the lesion, (2) the largest explorable area at the site of the lesion, (3) the relevancy of the selected Doppler parameter in order to take into account, as much as possible, the three dimensional configuration of the regurgitant jet. Moreover, this mapping procedure provides a pathophysiological insight of the regurgitant lesion for left-sided regurgitations.     

Transcatheter Aortic Valve Implantation Three-Dimensional Echo Monitoring and Guidance

Transcatheter aortic valve implantation (TAVI) was first performed in 2002. With the Edwards-Sapien valve, more than 20,000 to 25,000 TAVI procedures have now been performed worldwide. In this paper, we share our experience using live three-dimensional (3D) transesophageal echocardiography (TEE) to guide and monitor TAVI. At our medical center, we have performed more than 150 transfemoral TAVI procedures. Three-dimensional TEE is useful for precise measurement of the aortic annulus in multiple planes, confirming aortic valve stenosis severity and morphology, monitoring of the position of guidewires and catheters, identifying the ventricular and aortic edges of the valve stent, and optimizing bioprosthetic valve positioning. Post-deployment 3D TEE is also used to assess the severity of residual aortic regurgitation as well as to identify potential complications of the procedure including valve malpositioning.     

Quantifying Mitral Regurgitation: Added Value of Three-Dimensional Echocardiography

Current three-dimensional (3D) echocardiographic technology, including live 3D transesophageal echocardiography and single-beat 3D color Doppler imaging, are providing valuable new insight into the mechanism and quantification of mitral valve dysfunction. In this review we discuss important applications of 3D volumetric leaflet imaging with emphasis on the distinction between organic and functional mitral regurgitation. We also discuss the added benefit of current and emerging 3D color Doppler methods for the quantification of mitral regurgitation severity. The limitations of the 2D proximal isovelocity surface area method are discussed, along with potential solutions provided by 3D color Doppler imaging methods that do not require assumptions about the converging flow geometry. Methods to directly measure the vena contracta area of a regurgitant jet are presented along with recent validation studies comparing this method to a reference standard of cardiac MRI. In brief, we review the established and emerging applications of 3D color Doppler techniques for the quantification of mitral regurgitation severity.     

A new echocardiographic method for the assessment of the severity of aortic regurgitation: Color M-mode flow propagation velocity

PURPOSE: Echocardiographic Doppler methods widely used in assessment of the severity of aortic regurgitation (AR) are considered sensitive and reliable. However, they all have limitations for quantitation of AR. The color M-mode Doppler flow propagation velocity (FPV) method has been shown to provide useful insights in the evaluation of left ventricular diastolic function and appears to be minimally affected with preload changes. Clinical data regarding the value of FPV in the determination of the significance of valvular insuffiencies are lacking. The purpose of this study was to evaluate the use of FPV in measurement of the severity of AR and to compare its reliability with angiography and other echocardiographic methods. METHODS: Twenty-nine patients (13 male, 16 female) who had cardiac catheterization for various reasons before echocardiographic evaluation were included. The mean age was 53.6 +/- 13.4 years. At the time of cardiac catheterization, the degree of AR was assessed as mild in 10 patients, as moderate in 12, and as severe in 7. In all patients, FPV measurements of AR were obtained with color M-mode Doppler in the apical 5-chamber view. Regurgitation jet height and its ratio to left ventricular outflow obtained in the parasternal long axis with color flow Doppler, pressure half-time, and slope of AR obtained with continuous wave Doppler in apical 5-chamber view were other echocardiographic methods chosen for comparison. RESULTS: The mean values of FPV were 93.1 +/- 18.4 cm/s, 49.8 +/- 8.0 cm/s, and 31.7 +/- 4.9 cm/s in severe, moderate, and mild AR groups, respectively (P <.001). Significant correlation was observed between angiographic grades, FPV, pressure half-time, slope, and jet height and ratio to left ventricular outflow (P <.0001, r = 0.93; P <.0001, r = -0.81; P <.0001, r = 0.76; P <.0001, r = 0.92, respectively). CONCLUSION: FPV is a simple, practical, and reliable method for the quantification of AR.     

Profiles in Patient Safety: Confirmation Bias in Emergency Medicine

Confirmation bias is a pitfall in emergency care and may lead to inaccurate diagnoses and inappropriate treatments and care plans. Because of the increasing severity and volume of emergency care, emergency physicians often must rely on heuristics, such as rule‐out protocols, as a guide to diagnosing and treating patients. The use of heuristics or protocols can be potentially misleading if the initial diagnostic impression is incorrect. To minimize cognitive dissonance, clinicians may accentuate confirmatory data and ignore nonconfirmatory data. Clinicians should recognize confirmation bias as a potential pitfall in medical decision making in the emergency department. Reliance on the scientific method, Bayesian reasoning, metacognition, and cognitive forcing strategies may serve to improve diagnostic accuracy and improve patient care.     

动态三维超声重建定量测定主动脉瓣返流

为了评价Voxel模型动态三维超声重建定量测定主动脉瓣返流的准确性，我们对32例各种主动脉瓣关闭不全者的返流柱进行动态三维重建，对其中11例主动脉瓣返流柱的容积进行定量测定并与磁共振（MRI）对照。结果发现该技术能清晰地显示返流柱的形态及与周围结构的空间关系。返流柱的容积与MRI法测量结果的相关系数为0．91。作为半定量方法，使临床上判断返流严重程度更为精确，但对于返流柱的容积与近流程度之间的定量关系有待今后进一步研究。     

Echocardiographic quantitation of mitral regurgitation

Mitral valve regurgitation is a common valvular problem, particularly in developing nations. It causes significant morbidity and mortality, especially if the severity of valve regurgitation is underestimated. Echocardiography plays a significant role in the diagnoses, serial follow-up and management of patients with valvular heart disease. However, precise quantitation of the severity of mitral regurgitation is a crucial element in the therapeutic decisions for managing mitral regurgitation. An accurate assessment of the severity of mitral regurgitation allows for optimal timing of surgical intervention, culminating in improved patient outcomes. This review provides a systematic approach to the quantitation of mitral regurgitation using the echocardiography and Doppler methodologies that are available in the modern noninvasive imaging and hemodynamic laboratory. Additional, novel and evolving noninvasive imaging modalities are reviewed briefly.     

Echocardiographic quantitation of mitral regurgitation

Mitral valve regurgitation is a common valvular problem, particularly in developing nations. It causes significant morbidity and mortality, especially if the severity of valve regurgitation is underestimated. Echocardiography plays a significant role in the diagnoses, serial follow-up and management of patients with valvular heart disease. However, precise quantitation of the severity of mitral regurgitation is a crucial element in the therapeutic decisions for managing mitral regurgitation. An accurate assessment of the severity of mitral regurgitation allows for optimal timing of surgical intervention, culminating in improved patient outcomes. This review provides a systematic approach to the quantitation of mitral regurgitation using the echocardiography and Doppler methodologies that are available in the modern noninvasive imaging and hemodynamic laboratory. Additional, novel and evolving noninvasive imaging modalities are reviewed briefly.     

二尖瓣返流柱的经食管多平面体元模型动态三维超声重建

为了评价体元模型动态三维超声重建定量测定二尖瓣返流的准确性，我们对28例二尖瓣关闭不全者的返流柱进行动态三维重建；对8例二尖瓣返流柱的容积进行定量测定并与磁共振（MRI）对照。结果：该技术能清晰地显示返流柱的形态及与周围结构的空间关系，其图像所包含的信息量远超过二维法。返流束的空间分布与二尖瓣的基础病变有一定关系。三维提取技术定量测量返流柱的容积与MRI法测量结果的相关系数为0．85。该技术作为半定量方法，使临床上判断返流严重程度更为精确，但对于返流柱的容积与返流程度之间的定量关系有待今后进一步研究。     

Color flow imaging of the vena contracta in mitral regurgitation: technical considerations.

Qualitative grading of mitral regurgitation severity has significant pitfalls secondary to hemodynamic variables, sonographic technique, blood pool entrainment, and the Coanda effect. Volumetric and proximal isovelocity surface area methods can be used to quantitate regurgitant orifice area, regurgitant volume, and regurgitant fraction, but have several limitations and can pose technical challenges. The vena contracta width method provides a rapid and accurate quantitative assessment of mitral regurgitation severity, but is clinically underused. This article is intended to generate an understanding of the flow mechanics of the vena contracta and the sonographic technique required to provide consistent and accurate measurements of vena contracta width in patients with mitral regurgitation.     

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)     

Age-related prevalence of valvular regurgitation in normal subjects: a comprehensive color flow examination of 118 volunteers

We prospectively assessed the influence of aging on the prevalence of valvular regurgitation by using color flow imaging. One hundred eighteen healthy volunteers (21 to 82 years old) had a two-dimensional Doppler echocardiographic study that included color flow imaging to assess valvular regurgitation and that was semiquantitated by mapping the dimensions of the color flow regurgitant jet in orthogonal views. The subjects were divided into two groups: group 1 consisted of subjects who were younger than 50 years old (n = 61), and group 2 consisted of subjects who were at least 50 years old (n = 57). Mitral regurgitation was detected in 57 (48%) of the 118 subjects: 24 subjects (39%) in group 1 and 33 subjects (58%) in group 2. The severity of mitral regurgitation was trivial to mild. Aortic regurgitation was detected in 13 (11%) of the 118 subjects, all in group 2. The severity was trivial to mild. Tricuspid regurgitation was detected in 77 (65%) of the 118 subjects: 35 (57%) in group 1 and 42 (74%) in group 2. The severity was trivial to mild. Pulmonary regurgitation was detected in 24 (31%) of 78 subjects: nine (22%) in group 1 and 15 (41%) in group 2. The severity was trivial. These findings suggest that valvular regurgitation of a trivial or mild degree is a frequent finding in normal subjects and that it increases with age.     

Pulsed Doppler echocardiography in the assessment of tricuspid regurgitation

Pulsed Doppler echocardiography is a noninvasive method with high sensitivity and specificity for the assessment of tricuspid regurgitation. In patients with tricuspid regurgitation, pansystolic unusual Doppler signals are detected in the right atrial cavity, which are interpreted as tricuspid regurgitant flow signals. They distributed in a spindle-shaped area from the tricuspid orifice toward the right atrial posterior wall in parallel with the interatrial septum. The orientation of the range where the regurgitant Doppler signals are detected in the right atrial cavity shows the direction of the regurgitant jet. However, such a result is determined mainly in patients with functional tricuspid regurgitation. In regard to patients with organic tricuspid lesion, different considerations may be necessary. Semiquantitative grading of the severity of regurgitation is possible, based on the distance covered by the regurgitant signals from the tricuspid orifice. Tricuspid regurgitation is demonstrated also by contrast echocardiography. The severity is graded based on the distance reached by regurgitant curvilinear contrast echoes from the tricuspid valve in the M-mode echocardiography. If the ultrasound beam is adequately directed through the tricuspid orifice, the grade estimated by the contrast echoes are well correlated with that by the Doppler. However, if the M-mode is performed without the guide by the two-dimensional image, it may miss the most adequate beam direction for the observation, resulting in underestimating severity. The influences of tricuspid regurgitation are generally seen in the flow pattern of the major veins. However, they are more sharply reflected by the flow condition in the right atrial cavity than by the flows patterns in the major veins.     

Adaptive Color Gain for Vena Contracta Quantification in Valvular Regurgitation

Severe valvular regurgitation can lead to pulmonary hypertension, atrial fibrillation and heart failure. Vena contracta width is used to estimate the severity of the regurgitation. Parameters affecting visualization of color Doppler have a significant impact on the measurement. We propose a data-driven method for automated adjustment of color gain based on the peak power of the color Doppler signal in the vicinity of the vena contracta. A linear regression model trained on the peak power was used to predict the orifice diameter. According to our study, the color gain should be set to about 6?dB above where color Doppler data completely disappears from the image. Based on our method, orifices with reference diameters of 4, 6.5 and 8.5?mm were estimated with relative diameter errors within 18%, 12% and 14%, respectively.     

磁共振相位编码速度标识技术在儿童二尖瓣反流定量分析中应用

目的利用磁共振相位编码速度标识技术对儿童二尖瓣反流作定量分析。方法本组二尖瓣反流组共19例,男11例,女8例。正常对照组10例,男5例,女5例。19例二尖瓣反流病人先行心脏超声检查,利用半定量方法,诊断19例二尖瓣反流,轻度反流5例,中度反流10例,重度反流4例。利用磁共振的相位编码速度标识技术分别对正常对照组、二尖瓣轻、中、重度反流的病例进行左心室流入量和主动脉流量测定,随后对所测的结果进行统计学分析。结果在正常对照组中,左心室流入量与主动脉流量之间的相关性良好。正常组与轻度二尖瓣反流反流量与反流指数无显著性差异,正常组分别与中度、重度二尖瓣反流组反流量与反流指数有显著性差异,轻、中、重度二尖瓣反流组间有显著性差异,二尖瓣反流指数与超声的二尖瓣反流程度的估计相关性良好。结论磁共振相位编码速度标识技术为非创伤检查中对儿童二尖瓣反流定量分析的较好方法,并为以后的外科手术以及术后随访提供更为精确的信息。     

Importance of complex blood flow in the assessment of aortic regurgitation severity using phase contrast magnetic resonance imaging

This study aimed to investigate if and how complex flow influences the assessment of aortic regurgitation (AR) using phase contrast MRI in patients with chronic AR. Patients with moderate (n?=?15) and severe (n?=?28) chronic AR were categorized into non-complex flow (NCF) or complex flow (CF) based on the presence of systolic backward flow volume. Phase contrast MRI was performed repeatedly at the level of the sinotubular junction (Ao1) and 1 cm distal to the sinotubular junction (Ao2). All AR patients were assessed to have non-severe AR or severe AR (cut-off values: regurgitation volume (RVol)?≥?60 ml and regurgitation fraction (RF)?≥?50%) in both measurement positions. The repeatability was significantly lower, i.e. variation was larger, for patients with CF than for NCF (≥?12?±?12% versus?≥?6?±?4%, P?≤?0.03). For patients with CF, the repeatability was significantly lower at Ao2 compared to Ao1 (≥?21?±?20% versus?≥?12?±?12%, P?≤?0.02), as well as the assessment of regurgitation (RVol: 42?±?34 ml versus 54?±?42 ml, P?<?0.001; RF: 30?±?18% versus 34?±?16%, P?=?0.01). This was not the case for patients with NCF. The frequency of patients that changed in AR grade from severe to non-severe when the position of the measurement changed from Ao1 to Ao2 was higher for patients with CF compared to NCF (RVol: 5/26 (19%) versus 1/17 (6%), P?=?0.2; RF: 4/26 (15%) versus 0/17 (0%), P?=?0.09). Our study shows that complex flow influences the quantification of chronic AR, which can lead to underestimation of AR severity when using PC-MRI.

     

以立体角代替平面角彩色多普勒血流会聚法评估三尖瓣返流程度

目的　探讨彩色多普勒血流会聚法在评估三尖瓣返流程度中的应用价值。方法　应用不同的血流会聚方程对３２例三尖瓣返流患者的返流程度进行测量, 并与传统法所测指标进行比较。结果　应用立体角会聚方程计算的返流率（Ｆ２）与传统方法测得的返流束指标ＳＲ／ＳＲＡ、ＶＰ 以及二维多普勒方法计算的每搏返流量Ｑ之间的相关关系（ｒ分别为０．４８, ０．４６, ０．９８）优于应用平面角会聚方程计算的返流率（Ｆ１）, 与上述指标之间的相关关系（ｒ分别为０．４６, ０．４４, ０．９２）。而且ＳＶ１明显低估返流程度,ＳＶ２更接近于实际值。结论　应用立体角会聚方程代替平面角会聚方程能更为准确地评估三尖瓣返流程度     

Transesophageal color flow Doppler mapping in the assessment of native mitral valvular regurgitation: comparison with left ventricular angiography.

Transesophageal echocardiography (TEE) was performed within 24 hours after cardiac catheterization in 45 patients for assessment of native mitral valvular regurgitation. Color flow mapping was used in evaluating systolic regurgitant jet sizes. A jet demonstrated by TEE was 96% sensitive and 44% specific for angiographic mitral regurgitation. The presence of angiographic mitral regurgitation was best predicted by (single measurement) (1) a holosystolic jet, (2) a jet length greater than 2.5 cm, and (3) a jet area greater than 2 cm2. Severe angiographic mitral regurgitation (grades 3 and 4) was best predicted by (single measurement) (1) a jet area greater than 5 cm2, and (2) a jet length greater than 4 cm. It is concluded that the assessment of angiographic mitral regurgitation by TEE is improved by the measurement of these jet parameters, which have a high sensitivity and higher specificity than the presence of a jet alone. Furthermore, with TEE one is able to differentiate severe (grades 3 and 4) from absent or mild mitral regurgitation (grades 0, 1, and 2).     

Experience with qualitative and quantitative applications of doppler echocardiography in congenital heart disease

The increasing popularity of Doppler echocardiography in recent years has stemmed from the combination of Doppler with two-dimensional echocardiography, and from the Doppler capability for flow velocity measurement. In the past decade, Doppler instrumentation has evolved from single probe A- and M-mode systems with non-quantitative Doppler output, into multi-faceted instruments combining two-dimensional echo, M-mode echo, with both pulsed and continuous wave Doppler. In the field of pediatric cardiology, quantitative Doppler applications have proven most useful in noninvasive measurement of the severity of obstruction at aortic and pulmonic valves, and across pulmonary artery bands. High accuracy is enjoyed using either continuous wave, or high pulse repetition pulsed wave, Doppler. Additional quantitative applications include estimation of volume aortic flow (cardiac output), and comparison with volume pulmonic flow (pulmonary to systemic flow ratio). Through evaluation of specific disturbances of blood flow (timing, location, direction, duration), qualitative aspects of Doppler continue to provide sensitive and specific diagnosis of valvular disease, as well as shunt lesions such as atrial and ventricular septal defect, and patent ductus arteriosus. Qualitative Doppler offers ‘semi-quantitation’ of the severity of lesions based on demonstration of breadth and extent of the individual flow disturbances. The addition of Doppler flow information to the information available from conventional M-mode and two-dimensional echo has led to a comprehensive cardiac ultrasound capability. Information previously available only from invasive study (severity of gradient, shunt, regurgitation) is now available noninvasively; the impact upon current and long-term aspects of patient care should prove considerable.     

Brain natriuretic peptide and the severity of aortic regurgitation: is there any correlation?

We aimed to evaluate the correlation between aortic regurgitation severity and brain natriuretic (BNP) levels as a marker for left ventricular dysfunction. Sixty consecutive male patients (mean age 22 +/- 3 years) with isolated chronic aortic regurgitation were enrolled in the study together with a control group of 30 age-matched healthy volunteers (group A). Patients were classified with regard to aortic regurgitation vena contracta width as follows: group B, < 3 mm, mild (n = 16); group C, > or = 3 and < 6 mm, moderate (n = 26); group D, > or = 6 mm, severe (n = 18). BNP measurements were performed with a fluorescence immunoassay kit. BNP levels were increased in patients with aortic regurgitation, and severity of regurgitation had a significant influence on BNP levels. This effect can be explained by the volume loading effect of aortic regurgitation.