Valid and Reproducible Quantitative Assessment of Cardiac Volumes by Echocardiography in Patients with Valvular Heart Diseases-Possible or Wishful Thinking?

The analysis of left ventricular function is predominantly based on left ventricular volume assessment. Especially in valvular heart diseases, the quantitative assessment of total and effective stroke volumes as well as regurgitant volumes is necessary for a quantitative approach to determine regurgitant volumes and regurgitant fraction. In the literature, there is an ongoing discussion about differences between cardiac volumes estimated by echocardiography and cardiac magnetic resonance tomography. This viewpoint focuses on the feasibility to assess comparable cardiac volumes with both modalities. The former underestimation of cardiac volumes determined by 2D and 3D echocardiography is presumably explained by methodological and technical limitations. Thus, this viewpoint aims to stimulate an urgent and critical rethinking of the echocardiographic assessment of patients with valvular heart diseases, especially valvular regurgitations, because the actual integrative approach might be too error prone to be continued in this form. It should be replaced or supplemented by a definitive quantitative approach. Valid quantitative assessment by echocardiography is feasible once echocardiography and data analysis are performed with methodological and technical considerations in mind. Unfortunately, implementation of this approach cannot generally be considered for real-world conditions.

Plausible Functional Diagnostics by Rational Echocardiography in the Assessment of Valvular Heart Disease - Role of Quantitative Echocardiography in the Assessment of Mitral Regurgitation.

The echocardiographic assessment of valvular heart diseases is the basic analysis of valvular defects next to clinical investigation and stethoscopy. Severity of mitral regurgitation (MR) is usually estimated by an integrated approach using semi quantitative parameters and is still one of the biggest challenges of echocardiography. Quantitative echocardiographic analysis of MR severity often fails to describe comprehensible hemodynamic conditions. However, comprehensive echocardiography based on standardized image acquisition and proper image quality is required to properly assess hemodynamic parameter comparable to cardiac magnetic resonance tomography. This review focuses on the uncertainty of MR severity assessed by echocardiography in recent trials of interventional MR treatment. In addition, the necessity to provide plausible echocardiographic data for individual decision making is highlighted. In conclusion, plausible functional diagnostics by rational echocardiography is a prerequisite in patients with valvular heart diseases.

Echocardiographic assessment of mitral regurgitation: discussion of practical and methodologic aspects of severity quantification to improve diagnostic conclusiveness.

The echocardiographic assessment of mitral valve regurgitation (MR) by characterizing specific morphological features and grading its severity is still challenging. Analysis of MR etiology is necessary to clarify the underlying pathological mechanism of the valvular defect. Severity of mitral regurgitation is often quantified based on semi-quantitative parameters. However, incongruent findings and/or interpretations of regurgitation severity are frequently observed. This proposal seeks to offer practical support to overcome these obstacles by offering a standardized workflow, an easy means to identify non-severe mitral regurgitation, and by focusing on the quantitative approach with calculation of the individual regurgitant fraction. This work also indicates main methodological problems of semi-quantitative parameters when evaluating MR severity and offers appropriateness criteria for their use. It addresses the diagnostic importance of left-ventricular wall thickness, left-ventricular and left atrial volumes in relation to disease progression, and disease-related complaints to improve interpretation of echocardiographic findings. Finally, it highlights the conditions influencing the MR dynamics during echocardiographic examination. These considerations allow a reproducible, verifiable, and transparent in-depth echocardiographic evaluation of MR patients ensuring consistent haemodynamic plausibility of echocardiographic results.

Disproportionate mitral regurgitation: another myth? A critical appraisal of echocardiographic assessment of functional mitral regurgitation.

The contradictory findings of recent prospective randomized controlled trials assessing the impact of percutaneous edge-to-edge repair in patients with functional or secondary mitral regurgitation have triggered a lively discussion about an "integrated" echocardiographic approach for grading severity of mitral regurgitation. In the MITRA-FR trial, the COAPT trial and the REDUCE-FMR trial echocardiographic assessment of the severity of mitral regurgitation was consistent with principles set forth by the current echocardiographic guidelines and analysed in its best settings by expert international leaders in the field of echocardiography. However, serious inconsistencies appeared in the presented echocardiographic assessments regarding cardiac output and regurgitant fraction. A new term "disproportionate functional mitral regurgitation" was introduced describing a situation where the increase of effective regurgitant orifice area exceeds the enlargement of the left ventricular end-diastolic volumes. Further discussion resulted in the idea of a "new conceptional framework" for distinguishing "proportionate" and "disproportionate" functional mitral regurgitation. The aim of this viewpoint is to dispute conclusions based on the term "disproportionate" mitral regurgitation. A "disproportionate" FMR is highly questionable because disproportionateness of flow in communication vessels cannot exist. In addition, a proposal of echocardiographic assessment based on a conventional comprehensive transthoracic echocardiography is given to avoid obvious hemodynamic contradictions.

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.