Influence of left ventricular relaxation on the pressure half time of aortic regurgitation

2025 Expert Consensus Recommendations for the Diagnostic Requirements in Routine Practices of Transthoracic Echocardiography

Transthoracic echocardiography plays a crucial role in clinical diagnosis and is increasingly being used around the world. Comprehensive echocardiographic examinations require accurate measurements and the operators to have excellent technical skills. Despite the availability of several published echocardiographic guidelines, the absence of recommended operational manuals in daily practice has resulted in significant variation in the content of echocardiography reports across different medical institutions. This variability has created communication barriers between medical institutions and also hampered the development of a national echocardiography database in Taiwan. Balancing quality and efficiency is a critical concern in echocardiography, and most published guidelines for echocardiography primarily focus on disease categorization. In the current document, we focus on information about the scanning sequence, including scanning techniques, common pitfalls, simple disease interpretation, and the recommended intensity. Based on a growing body of research, we particularly emphasize right-sided imaging and measurement information. We also discuss equipment settings, which have often been overlooked but are essential to obtaining good imaging and accurate measurements. Our recommendations could enhance clinicians' and sonographers' understanding of the core aspects of echocardiography and were developed with consideration of the health-care payment system in Taiwan. Implementing our recommendations may subsequently enable the establishment of a national echocardiography database in Taiwan.

Echocardiographic assessment of aortic regurgitation: a narrative review

Aortic regurgitation (AR) is the third most frequently encountered valve lesion and may be caused by abnormalities of the valve cusps or the aorta. Echocardiography is instrumental in the assessment of AR as it enables the delineation of valvular morphology, the mechanism of the lesion and the grading of severity. Severe AR has a major impact on the myocardium and carries a significant risk of morbidity and mortality if left untreated. Established and novel echocardiographic methods, such as global longitudinal strain and three-dimensional echocardiography, allow an estimation of this risk and provide invaluable information for patient management and prognosis. This narrative review summarises the epidemiology of AR, reviews current practices and recommendations with regards to the echocardiographic assessment of AR and outlines novel echocardiographic tools that may prove beneficial in patient assessment and management.

Beyond Aortic Stenosis: Addressing the Challenges of Multivalvular Disease Assessment

Aortic stenosis (AS) can often coexist with other valvular diseases or be combined with aortic regurgitation (AR), leading to unique pathophysiological conditions. The combination of affected valves can vary widely, resulting in a lack of standardized diagnostic or therapeutic approaches. Echocardiography is crucial in assessing patients with valvular heart disease (VHD), but careful consideration of the hemodynamic interactions between combined valvular defects is necessary. This is important as it may affect the reliability of commonly used echocardiographic parameters, making the diagnosis challenging. Therefore, a multimodality imaging approach, including computed tomography or cardiac magnetic resonance, is often not just beneficial but crucial. It represents the future of diagnostics in this intricate field due to its unprecedented capacity to quantify and comprehend valvular pathology. The absence of definitive data and guidelines for the therapeutic management of AS in the context of multiple valve lesions makes this condition particularly challenging. As a result, an individualized, case-by-case approach is necessary, guided primarily by the recommendations for the predominant valve lesion. This review aims to summarize the pathophysiology of AS in the context of multiple and mixed valve disease, with a focus on the hemodynamic implications, diagnostic challenges, and therapeutic options.

Patient-specific, echocardiography compatible flow loop model of aortic valve regurgitation in the setting of a mechanical assist device

Background

Aortic regurgitation (AR) occurs commonly in patients with continuous-flow left ventricular assist devices (LVAD). No gold standard is available to assess AR severity in this setting. Aim of this study was to create a patient-specific model of AR-LVAD with tailored AR flow assessed by Doppler echocardiography.

Methods

An echo-compatible flow loop incorporating a 3D printed left heart of a Heart Mate II (HMII) recipient with known significant AR was created. Forward flow and LVAD flow at different LVAD speed were directly measured and AR regurgitant volume (RegVol) obtained by subtraction. Doppler parameters of AR were simultaneously measured at each LVAD speed.

Results

We reproduced hemodynamics in a LVAD recipient with AR. AR in the model replicated accurately the AR in the index patient by comparable Color Doppler assessment. Forward flow increased from 4.09 to 5.61 L/min with LVAD speed increasing from 8,800 to 11,000 RPM while RegVol increased by 0.5 L/min (2.01 to 2.5 L/min).

Conclusions

Our circulatory flow loop was able to accurately replicate AR severity and flow hemodynamics in an LVAD recipient. This model can be reliably used to study echo parameters and aid clinical management of patients with LVAD.

Relation of Transthoracic Echocardiographic Aortic Regurgitation to Pressure Half-time and All-Cause Mortality

To evaluate the relation of aortic regurgitation (AR) pressure half-time (PHT) on transthoracic echocardiography (TTE) and all-cause mortality, we screened 118,647 baseline TTE reports from 2000 to 2017, to identify patients with any AR and PHT data. Patients with infective endocarditis or previous aortic valve replacement were excluded. The relation of baseline PHT on time to all-cause mortality was evaluated using Cox regression. A total of 2,653 patients were included (73.1 ± 14.3 years; 53.8% female; PHT, 530 ± 162 ms). Patients with shorter PHTs more frequently had 3-4+ AR (PHT ≤ 200 ms vs > 500 ms, 17.9% vs 0.6%, p < 0.0001). Diastolic parameters (E/e', E/A ratio, mitral valve deceleration time, and pulmonary artery systolic pressure) all significantly correlated with PHT (all p < 0.05). Over a median (IQR) follow-up of 8 (4 to 11 years), there were 799 (30.1%) deaths at a median (IQR) of 1.9 (0.4 to 4.3) years. On a univariate basis, a PHT ≤ 320 ms or > 750 ms was significantly related to increased mortality, even amongst those with nonsevere AR. After multivariable adjustment (in particular for E/e'), PHT was no longer significantly related to death. In conclusion, in this large, single center, retrospective study, AR PHT was not independently related to mortality. While a PHT ≤ 320 ms was associated with increased mortality in patients without severe AR, this relation was no longer significant after adjusting for diastolic functional variables. Thus, a PHT ≤ 320 ms in patients without significant AR may indicate prognostically-relevant diastolic dysfunction.

Distinct pressure half-time values by transthoracic echocardiography for grading of paravalvular regurgitation after transcatheter aortic valve replacement

Postprocedural aortic regurgitation (AR) has negative impact on patient outcome after transcatheter aortic valve replacement (TAVR). Standard assessment of AR severity by echocardiography is hampered after TAVR. Measurement of pressure half-time (PHT) by echocardiography is not limited in these patients but it may be affected by concomitant left ventricular hypertrophy (LVH). This study sought to evaluate distinct cut-off values of PHT differentiating between patients without and with more than mild LVH for grading of AR after TAVR with cardiac magnetic resonance (CMR) as the reference method for comparison. 71 patients (age 81 ± 6 years) with severe aortic stenosis undergoing TAVR were included into the study. Transthoracic echocardiography (TTE) and CMR were performed after TAVR. Left ventricular mass index was calculated by TTE. PHT was measured by continuous-wave Doppler echocardiography of aortic regurgitation jet. In 18 patients (25%) PHT could not be obtained due to no or very faint Doppler signal. Aortic regurgitant volume and regurgitant fraction were calculated by CMR by flow analysis of the ascending aorta. In 14 of 53 patients (26%) AR after TAVR was moderate or severe as categorized by CMR analysis. More than mild LVH was present in 27 of 53 patients (51%). PHT correlated inversely less to regurgitant fraction by CMR analysis in patients with LVH (r = −0.293; p = 0.138) than in patients without LVH (r = −0.455; p = 0.020). In patients without relevant LVH accuracy of PHT to predict moderate or severe paravalvular regurgitation AUC was 0.813 using a cut-off value of 347 ms and AUC was 0.729 in patients with more than mild LVH using a cut-off value of 420 ms. Analysis of PHT by TTE with distinct cut-off values for patients without and with more than mild LVH allows detection of moderate or severe AR after TAVR as defined by CMR. In none of the patients in which PHT could not be measured AR was categorized as more than trace by CMR analysis.

Expert consensus document on the assessment of the severity of aortic valve stenosis by echocardiography to provide diagnostic conclusiveness by standardized verifiable documentation

According to recent recommendations on echocardiographic assessment of aortic valve stenosis direct measurement of transvalvular peak jet velocity, calculation of transvalvular mean gradient from the velocities using the Bernoulli equation and calculation of the effective aortic valve area by continuity equation are the appropriate primary key instruments for grading severity of aortic valve stenosis. It is obvious that no gold standard can be declared for grading the severity of aortic stenosis. Thus, conclusions of the exclusive evaluation of aortic stenosis by Doppler echocardiography seem to be questionable due to the susceptibility to errors caused by methodological limitations, mathematical simplifications and inappropriate documentation. The present paper will address practical issues of echocardiographic documentation to satisfy the needs to analyze different scenarios of aortic stenosis due to various flow conditions and pressure gradients. Transesophageal and multidimensional echocardiography should be implemented for reliable measurement of geometric aortic valve area and of cardiac dimensions at an early stage of the diagnostic procedure to avoid misinterpretation due to inconsistent results.

Aortic Insufficiency

Echocardiography is a reliable and reproducible method for evaluation of aortic insufficiency (AI). AI has a variety of etiologies, including congenital or acquired, and may present as an acute situation or as a chronic condition. Regardless of the clinical presentation, patient symptoms and physical signs may not be present unless the AI has progressed to a moderate or severe degree. As the severity of AI increases, there are changes in the pathophysiology of the heart, including an increase in left ventricle dimensions and chamber compliance. Echocardiographic methods to evaluate AI include two-dimensional, m-mode, color flow imaging, and pulsed wave and continuous wave Doppler. The combined use of multiple techniques provides more thorough and accurate quantification, both during follow-up of the disease process and after surgical correction.