Proximal Flow Convergence Method Research Articles

Quantification of primary mitral regurgitation by echocardiography: A practical appraisal.

The accurate quantification of primary mitral regurgitation (MR) and its consequences on cardiac remodeling is of paramount importance to determine the best timing for surgery in these patients. The recommended echocardiographic grading of primary MR severity relies on an integrated multiparametric approach. It is expected that the large number of echocardiographic parameters collected would offer the possibility to check the measured values regarding their congruence in order to conclude reliably on MR severity. However, the use of multiple parameters to grade MR can result in potential discrepancies between one or more of them. Importantly, many factors beyond MR severity impact the values obtained for these parameters including technical settings, anatomic and hemodynamic considerations, patient's characteristics and echocardiographer' skills. Hence, clinicians involved in valvular diseases should be well aware of the respective strengths and pitfalls of each of MR grading methods by echocardiography. Recent literature highlighted the need for a reappraisal of the severity of primary MR from a hemodynamic perspective. The estimation of MR regurgitation fraction by indirect quantitative methods, whenever possible, should be central when grading the severity of these patients. The assessment of the MR effective regurgitant orifice area by the proximal flow convergence method should be used in a semi-quantitative manner. Furthermore, it is crucial to acknowledge specific clinical situations in MR at risk of misevaluation when grading severity such as late-systolic MR, bi-leaflet prolapse with multiple jets or extensive leak, wall-constrained eccentric jet or in older patients with complex MR mechanism. Finally, it is debatable whether the 4-grades classification of MR severity would be still relevant nowadays, since the indication for mitral valve (MV) surgery is discussed in clinical practice for patients with 3+ and 4+ primary MR based on symptoms, specific markers of adverse outcome and MV repair probability. Primary MR grading should be seen as a continuum integrating both quantification of MR and its consequences, even for patients with presumed "moderate" MR.

Comparison of Mitral Regurgitant Volume Assessment between Proximal Flow Convergence and Volumetric Methods in Patients with Significant Primary Mitral Regurgitation: An Echocardiographic and Cardiac Magnetic Resonance Imaging Study

Discrepancies have been observed between transthoracic echocardiography (TTE) and cardiac magnetic resonance imaging (CMR) severity grading in primary mitral regurgitation (MR). We sought to compare mitral regurgitant volume (RVol) determined by the TTE proximal flow convergence (proximal isovelocity surface area [PISA]) method and by volumetric methods (TTE and CMR) and to study the relationship between left ventricle (LV) size and RVol obtained by either the PISA or volumetric methods. Two centers prospectively recruited 188 patients with at least moderate to severe primary MR due to prolapse in sinus rhythm who underwent TTE and CMR examinations. Regurgitant volume was estimated by either PISA (PISA-RVol) or volumetric methods (LV total stroke volume-systolic aortic forward outflow volume) using either CMR (CMR-RVol) or TTE (TTE-RVol). The PISA-RVol was weakly correlated with CMR-RVol and TTE-RVol (r=0.29 and 0.30, respectively; P<.001 for both). On multivariable analysis, smaller CMR-left ventricular end-diastolic volume (LVEDV) and absence of mitral annular disjunction independently correlated with increased magnitude of RVol difference between PISA and volumetric methods. While PISA-RVol and LVEDV were unrelated, CMR-RVol and TTE-RVol moderately correlated with LVEDV (r=0.66 and 0.68, respectively; P<.001 for both). In contrast, LVEDV and regurgitant fraction (RVol/LVtotal stroke volume), assessed with either TTE or CMR, were poorly correlated (r=0.17, P=.02; and r=0.12, P=.10, respectively). Mitral RVol values estimated by PISA and volumetric methods are not directly comparable. The expected proportional relationship between volumetric RVol and LV size, which was not observed with PISA-RVol, suggests that PISA-RVol would be inaccurate. Given that RVol assessed with volumetric methods depends on LV size, determination of a unique RVol threshold for severe MR is challenging. In contrast to RVol, calculating regurgitant fraction by volumetric methods allows the quantification of MR severity independently from LV size.

Comparison of mitral regurgitant volume assessment between proximal flow convergence and volumetric methods in patients with significant primary mitral regurgitation

Abstract Funding Acknowledgements Type of funding sources: None. Background. Discrepancies have been observed between transthoracic echocardiography (TTE) and cardiac magnetic resonance imaging (MRI) severity grading in primary mitral regurgitation (MR). Purpose. To compare mitral regurgitant volume (RV) obtained by the proximal flow convergence method (PISA) method by TTE and by volumetric methods (TTE and MRI), and study the relationship between LV size and RV obtained by either the PISA or volumetric methods. Methods and results. 188 patients from 2 heart valve clinics with at least moderate-to-severe primary MR due to prolapse in sinus rhythm who underwent evaluation with TTE and MRI were included. RV was estimated by either PISA or volumetric methods (Left ventricular [LV] stroke volume minus systolic aortic outflow volume)) by either MRI (MRI-RV) or TTE (TTE-RV)). PISA-RV and either MRI-RV or TTE-RV weakly correlated (r = 0.29 and 0.30,p &amp;lt; 0.001). On multivariable analysis, LV end-diastolic volume (LVEDV) and bileaflet prolapse independently correlated with the magnitude of the difference between PISA and volumetric methods. While PISA-RV and LVEDV were unrelated, MRI-RV and TTE-RV strongly correlated with LVEDV (r = 0.66 and 0.68,p &amp;lt; 0.001). In contrast, LVEDV and regurgitant fraction (RF = RV/LVEDV) either with TTE or MRI were poorly related (r = 0.17,p = 0.02 and r = 0.12,p = 0.10). Conclusion. RV estimated by the PISA and volumetric methods are not comparable. The expected proportional relationship between volumetric RV and LV size, which is not observed with PISA-RV suggests the inaccuracy of PISA-RV. Given that RV by volumetric methods depends on LV size, determination of a unique RV threshold for severe MR is challenging. Calculation of RF may overcome this limitation. Abstract Figure. RV assessed by PISA or volumetric method Abstract Figure. Illustrative example

P1580 Global regurgitant volume - approaching the critical mass in valvular-driven heart failure

Abstract Aims Recent progress in the diagnosis of functional valve regurgitation forms a coherent perception of severity thresholds by quantitative assessment. However, thresholds focused on either valve in isolation -not accounting for the global hemodynamic burden arising from concomitant functional regurgitation of the mitral and tricuspid valves. We sought to determine whether the global regurgitant volume is associated with adverse cardiac remodeling and mortality. Methods and results This long-term observational study included 414 patients on guideline-directed medical therapy. Baseline global regurgitant load defined as the sum of mitral and tricuspid regurgitant volume was assessed by the proximal flow convergence method. All-cause mortality during five years follow-up served as the primary endpoint. The median global regurgitant load was 30ml (IQR 15-49) with 67% accounting for mitral and 33% accounting for tricuspid regurgitant volume. The global regurgitant load had significant impact on outcome with a crude HR of 1.46 (1.28-1.66; P &amp;lt; 0.001) for a 1-SD increase in global regurgitant volume, results that remained virtually unchanged after bootstrap or clinical confounder-based adjustment (P &amp;lt; 0.001 for adjusted models). Spline curve analysis showed a linearly increasing risk with a threshold of 50ml and sustained increasing risk thereafter. Conclusions The present study demonstrates the detrimental effect of the global regurgitant load in patients with HFrEF. The threshold where heart failure is driven by the valve lesions is a global regurgitant volume of 50ml with continuously increasing risk beyond that threshold. Future studies need to address whether an attempt to reduce the global regurgitant volume can improve outcome. Abstract P1580 Figure 1 - Global RegVol

Clinical Situations Associated with Inappropriately Large Regurgitant Volumes in the Assessment of Mitral Regurgitation Severity Using the Proximal Flow Convergence Method in Patients with Chordae Rupture

Regurgitant volume (RVol) calculated using the proximal flow convergence method (proximal isovelocity surface area [PISA]) has been accepted as a key quantitative parameter for the diagnosis of and clinical decision-making with regard to severe mitral regurgitation (MR). However, a recent prospective study showed a significant overestimation of RVol by the echocardiographic PISA method compared with the MR volume measured using magnetic resonance imaging. We aimed to evaluate the frequency of overestimation of RVol by the PISA method and the clinical conditions that require a different quantitative method to correct the overestimation. We retrospectively enrolled 166 consecutive patients with degenerative MR and chordae rupture, in whom RVol was measured using both the PISA and two-dimensional Doppler volumetric methods. The volumetric method was used to measure total stroke volume using the two-dimensional Simpson biplane method, and forward stroke volume was measured using pulsed Doppler tracing at the left ventricular (LV) outflow tract. RVol by the volumetric method was calculated using total stroke volume - forward stroke volume. Severe MR was defined as an RVol >60mL. All patients had severe MR based on RVol by the PISA method, but 68 (41.1%) showed RVol by the volumetric method values of <60mL, resulting in discordant results. The patients with discordant results were characterized by a higher prevalence of female sex, lower body surface area, smaller LV diastolic and systolic dimensions and volumes, smaller left atrial volume, smaller PISA angle, and lower frequency of flail leaflets (39.7% vs 62.2%, P=.004). Multivariate analysis revealed that LV end-diastolic volume (LVEDV) and PISA angle were independent factors, with the best cutoff LVEDV and PISA angle being 173mL and 103°, respectively. During follow-up (median, 3.4years; interquartile range, 2.0-4.8years), mitral valve repair and replacement were performed in 103 and six patients, respectively. The 2-year mitral valve surgery-free survival rate was higher in the discordant group (51.8%±0.06% vs 31.2%±0.05%, P<.001). Even in the patients with documented chordae rupture, the PISA method alone resulted in inappropriate overestimation of MR severity in a significant proportion of patients. Thus, an additive quantitative method is absolutely necessary in patients with a small LVEDV or narrow PISA angle.

Global regurgitant volume: approaching the critical mass in valvular-driven heart failure.

Recent progress in the diagnosis of functional valve regurgitation forms a coherent perception of severity thresholds by quantitative assessment. However, thresholds focused on either valve in isolation-not accounting for the global haemodynamic burden arising from concomitant functional regurgitation of the mitral and tricuspid valves. We sought to determine whether the global regurgitant volume is associated with adverse cardiac remodelling and mortality. This long-term observational study included 414 patients on guideline-directed medical therapy. Baseline global regurgitant load defined as the sum of mitral and tricuspid regurgitant volume was assessed by the proximal flow convergence method. All-cause mortality during 5 years follow-up served as the primary endpoint. The median global regurgitant load was 30 mL (interquartile range 15-49) with 67% accounting for mitral and 33% accounting for tricuspid regurgitant volume. The global regurgitant load had significant impact on outcome with a crude hazard ratio of 1.46 (1.28-1.66; P < 0.001) for a 1-SD increase in global regurgitant volume, results that remained virtually unchanged after bootstrap or clinical confounder-based adjustment (P < 0.001 for adjusted models). Spline curve analysis showed a linearly increasing risk with a threshold of 50 mL and sustained increasing risk thereafter. The present study demonstrates the detrimental effect of the global regurgitant load in patients with heart failure with reduced ejection fraction. The threshold where heart failure is driven by the valve lesions is a global regurgitant volume of 50 mL with continuously increasing risk beyond that threshold. Future studies need to address whether an attempt to reduce the global regurgitant volume can improve outcome.

P1758Clinical situations associated with inappropriately large regurgitant volume in the assessment of mitral regurgitation severity using proximal flow convergence method

P1758Clinical situations associated with inappropriately large regurgitant volume in the assessment of mitral regurgitation severity using proximal flow convergence method

Impact of a Geometric Correction for Proximal Flow Constraint on the Assessment of Mitral Regurgitation Severity Using the Proximal Flow Convergence Method.

BackgroundOverestimation of the severity of mitral regurgitation (MR) by the proximal isovelocity surface area (PISA) method has been reported. We sought to test whether angle correction (AC) of the constrained flow field is helpful to eliminate overestimation in patients with eccentric MR.MethodsIn a total of 33 patients with MR due to prolapse or flail mitral valve, both echocardiography and cardiac magnetic resonance image (CMR) were performed to calculate regurgitant volume (RV). In addition to RV by conventional PISA (RVPISA), convergence angle (α) was measured from 2-dimensional Doppler color flow maps and RV was corrected by multiplying by α/180 (RVAC). RV measured by CMR (RVCMR) was used as a gold standard, which was calculated by the difference between total stroke volume measured by planimetry of the short axis slices and aortic stroke volume by phase-contrast image.ResultsThe correlation between RVCMR and RV by echocardiography was modest [RVCMR vs. RVPISA (r = 0.712, p < 0.001) and RVCMR vs. RVAC (r = 0.766, p < 0.001)]. However, RVPISA showed significant overestimation (RVPISA - RVCMR = 50.6 ± 40.6 mL vs. RVAC - RVCMR = 7.7 ± 23.4 mL, p < 0.001). The overall accuracy of RVPISA for diagnosis of severe MR, defined as RV ≥ 60 mL, was 57.6% (19/33), whereas it increased to 84.8% (28/33) by using RVAC (p = 0.028).ConclusionConventional PISA method tends to provide falsely large RV in patients with eccentric MR and a simple geometric AC of the proximal constraint flow largely eliminates overestimation.

Proximal Flow Convergence Method by Three-Dimensional Color Doppler Echocardiography for Mitral Valve Area Assessment in Rheumatic Mitral Stenosis

The two-dimensional (2D) proximal isovelocity surface area (PISA) method has important technical limitations for mitral valve orifice area (MVA) assessment in mitral stenosis (MS), mainly the geometric assumptions of PISA shape and the requirement of an angle correction factor. Single-beat real-time three-dimensional (3D) color Doppler imaging allows the direct measurement of PISA without geometric assumptions or the requirement of an angle correction factor. The aim of this study was to validate this method in patients with rheumatic MS. Sixty-three consecutive patients with rheumatic MS were included. MVA was assessed using the transthoracic 2D and 3D PISA methods. Planimetry of MVA (2D and 3D) and the pressure half-time method were used as reference methods. The 3D PISA method had better correlations with the reference methods (with 2D planimetry, r = 0.85, P < .001; with 3D planimetry, r = 0.89, P < .001; and with pressure half-time, r = 0.85, P < .001) than the conventional 2D PISA method (with 2D planimetry, r = 0.63, P < .001; with 3D planimetry, r = 0.66, P < .001; and with pressure half-time, r = 0.68, P < .001). In addition, a consistent significant underestimation of MVA using the conventional 2D PISA method was observed. A high percentage (30%) of patients with nonsevere MS by 3D planimetry were misclassified by the 2D PISA method as having severe MS (effective regurgitant orifice area < 1 cm(2)). In contrast, the 3D PISA method had 94% agreement with 3D planimetry. Good intra- and interobserver agreement for 3D PISA measurements were observed, with intraclass correlation coefficients of 0.95 and 0.90, respectively. MVA assessment using PISA by single-beat real-time 3D color Doppler echocardiography is feasible in the clinical setting and more accurate than the conventional 2D PISA method.

Quantification of aortic regurgitation using proximal isovelocity surface area: an effective segmentation approach based on fuzzy clustering

Echocardiography is mainly to assess valvular regurgitation and get valuable information on the severity of aortic regurgitation (AR). It has several applications, but this paper focuses only on its use in the quantitative evaluation of AR. Proximal isovelocity surface area (PISA) evaluates the severity of AR. The quantification of the effective regurgitant orifice area (EROA) in AR is presented utilising Doppler echocardiography aided by clustering based image segmentation and PISA techniques. Pre-processing is done subjecting the colour Doppler echocardiography image to Gaussian filtering which improves the signal to noise ratio of the image. Subsequently, the image was enhanced with the aid of an image contrast enhancement method that utilises contrast-limited adaptive histogram equalisation. Then this image is segmented by using fuzzy-k means clustering to enable more precise quantification of the AR. PISA method is employed for calculating the quantitative parameters of AR such as, EROA, regurgitant volume (RV), regurgitant fraction (RF), etc. The proximal flow convergence method is used to quantify valvular regurgitation by analysing the converging flow field proximal to the mild, severe or eccentric AR lesion. Experimental evaluation on the commonly accessible dataset illustrates the enhanced performance of the proposed approach effectively.

Comparison of Direct Planimetry of Mitral Valve Regurgitation Orifice Area by Three-Dimensional Transesophageal Echocardiography to Effective Regurgitant Orifice Area Obtained by Proximal Flow Convergence Method and Vena Contracta Area Determined by Color Doppler Echocardiography

Direct measurement of anatomic regurgitant orifice area (AROA) by 3-dimensional transesophageal echocardiography was evaluated for analysis of mitral regurgitation (MR) severity. In 72 patients (age 70.6 ± 13.3 years, 37 men) with mild to severe MR, 3-dimensional transesophageal echocardiography and transthoracic color Doppler echocardiography were performed to determine AROA by direct planimetry, effective regurgitant orifice area (EROA) by proximal convergence method, and vena contracta area (VCA) by 2-dimensional color Doppler echocardiography. AROA was measured with commercially available software (QLAB, Philips Medical Systems, Andover, Massachusetts) after adjusting the first and second planes to reveal the smallest orifice in the third plane where planimetry could take place. AROA was classified as circular or noncircular by calculating the ratio of the medial-lateral distance above the anterior-posterior distance (≤1.5 compared to >1.5). AROA determined by direct planimetry was 0.30 ± 0.20 cm², EROA determined by proximal convergence method was 0.30 ± 0.20 cm², and VCA was 0.33 ± 0.23 cm². Correlation between AROA and EROA (r = 0.96, SEE 0.058 cm²) and between AROA and VCA (r = 0.89, SEE 0.105 cm²) was high considering all patients. In patients with a circular regurgitation orifice area (n = 14) the correlation between AROA and EROA was better (r = 0.99, SEE 0.036 cm²) compared to patients with noncircular regurgitation orifice area (n = 58, r = 0.94, SEE 0.061 cm²). Correlation between AROA and EROA was higher in an EROA ≥0.2 cm² (r = 0.95) than in an EROA <0.2 cm² (r = 0.60). In conclusion, direct measurement of MR AROA correlates well with EROA by proximal convergence method and VCA. Agreement between methods is better for patients with a circular regurgitation orifice area than in patients with a noncircular regurgitation orifice area.

An efficient approach for quantification of aortic regurgitation using proximal isovelocity surface area method

The proximal isovelocity surface area measurement, also called as the "flow convergence" method, can be used in echocardiography to estimate the area of an orifice through which blood flows. It has a lot of applications, but this paper focuses only on its use in the quantitative evaluation of aortic regurgitation. Proximal isovelocity surface area has been anticipated as a quantitative method to evaluate the severity of aortic regurgitation, In this paper, we present an effective approach based on an Image processing techniques which can accurately quantify the effective regurgitates orifice area (EROA) in aortic regurgitation by using the Doppler Echocardiography image with the aid of proximal isovelocity surface area. In the pre-processing stage, the color Doppler echocardiography image with RGB color space has been subjected to Wiener filtering. Subsequently it has been quantized with the aid of color quantization by using NBS/ISCC color space, which has made the quantification of aortic regurgitation color Doppler echocardiography image more accurate. Moreover that, the proximal isovelocity surface area (PISA) method is employed for calculation of quantitative parameters such as effective regurgitant orifice (ERO), Regurgitant volume, Regurgitant Fraction and more of aortic regurgitation (AR). The proximal flow convergence method has been exploited to quantify valvular regurgitation by the analysis of the converging flow field proximal to assess the mildness, severity and eccentricity of an aortic regurgitant lesion. Experimental evaluation on the commonly accessible dataset illustrates the enhanced performance of the proposed effective approach for the quantification of aortic regurgitation.

Evaluation of the Severity of Mitral Valvular Regurgitation with Doppler Echo-Cardiography Using Proximal Flow Convergence Method

Evaluation of the Severity of Mitral Valvular Regurgitation with Doppler Echo-Cardiography Using Proximal Flow Convergence Method

Evaluation of the Severity of Mitral Valvular Regurgitation with Doppler Echocardiography Using Proximal Flow Convergence Method

Problem statement: Valvular regurgitation is recognized as the central cause of morbidity and mortality. Even though the clinician can detect the presence of regurgitation by mere physical examination; diagnostic methods become inevitable while estimating the severity of valvular regurgitation and in the transformation of cardiac chambers as in reaction to the volume overload condition. Lately, a promising new technology, the Echocardiography with Doppler is found to facilitate the non-invasive recognition and assessment of the severity and etiology of valvular regurgitation. Accurate measurements of regurgitant volume in patients is of utmost importance since it aids in the estimation of the progression of the disease which in turn is vital for determining the optimal time for surgical repair or replacement. Approach: Color space conversion and anisotropic diffusion segmentation techniques are utilized in this study for the pre-processing stage of the quantification of mitral regurgitation. Flow field measurements are carried out with the aid of proximal flow convergence method. Results: A calculated value of flow rate, regurgitant orifice area, regurgitant fraction and the regurgitant volume for a regurgitant orifice in the cardiovascular system are obtained from the potential Color Doppler visualization of the flow convergence region. Conclusion: The research proposed provides a significant assessment of the echocardiographic and Doppler techniques employed in the evaluation of mitral valvular regurgitation in the patients. Additionally it also proffers the estimation of mildness, severity and eccentricity of mitral valvular regurgitation on basis of the scientific literature and a consensus of a panel of experts.

Evaluation of the Severity of Mitral Valvular Regurgitation with Doppler Echocardiography Using Proximal Flow Convergence Method

Evaluation of the Severity of Mitral Valvular Regurgitation with Doppler Echocardiography Using Proximal Flow Convergence Method

Electrical Conduction Disturbance Effects on Dynamic Changes of Functional Mitral Regurgitation

The aim of this study was to investigate the relationship between dynamics of functional mitral regurgitation (MR) and the degree of electrical conduction disturbance, and to evaluate the impact of cardiac resynchronization therapy (CRT) on MR severity and its phasic pattern. Mechanisms of phasic changes of functional MR, which may be determined by annulus dilation and tethering of the leaflet, remain unclear. Transthoracic two-dimensional echocardiography was performed in 60 patients with functional MR. A biventricular pacemaker was implanted in 19 patients. The mitral annulus area (MAA) and the tenting area (TA) were measured from apical views. The MR volume and fraction were assessed by the quantitative pulsed Doppler method. Instantaneous regurgitation flow rate was measured by proximal flow convergence method. A dynamic change in MR flow rate was evaluated by frame-by-frame analysis throughout systole. A phasic pattern with two peaks at early- and late-systole and decrease in mid-systole was noticed in 57 patients. The early-systolic peak of MR was larger than the late-systolic peak (128.4 +/- 64.3 ml/s vs. 73.9 +/- 55.1 ml/s, p < 0.001). The ratio of flow rate at these two peaks correlated with QRS duration (r = 0.55, p < 0.001). Early-systolic flow rate reduced after CRT (143.9 +/- 60.8 ml/s to 90.7 +/- 54.1 ml/s, p < 0.05), but late-systolic flow rate did not (61.5 +/- 55.0 ml/s to 51.2 +/- 40.9 ml/s, p = NS). A similar pattern was observed for TA, whereas MAA did not change after CRT. Biphasic pattern was found in functional MR, and the ratio of flow rate at two peaks correlated with QRS duration. The CRT decreased regurgitation flow volume by reducing early-systolic MR but not late-systolic MR, resulting in the change in phasic pattern of functional MR.

Value of the proximal flow convergence method for quantification of the regurgitant volume in mitral regurgitation

The purpose of this study was to evaluate whether the underlying mechanism of mitral regurgitation influences the reliability of the proximal flow con- vergence method to assess the regurgitant volume. Furthermore, the mode of imaging the flow convergence region and different correction algorithms for calculation of the regurgitant volume were compared. Regurgitant volume was assessed in 45 patients (age 61+/-13 years) with organic (n=19) and functional (n=26) mitral regurgitation by the proximal flow convergence method for aliasing velocities between 14 and 64 cm/s using two-dimensional color Doppler imaging. Different correction and calculation algorithms were compared. In addition, regurgitant volume was determined using color Doppler M-mode for an aliasing velocity of 28 cm/s. The quantitative Doppler method was used as reference. In organic mitral regurgitation correlation coefficients (mean differences) between the proximal flow convergence method and the reference method were 0.25-0.43/ 0.58-0.67 (46-111 ml/15-17 ml) before/after geometric correction of the regurgitant volume for the aliasing velocities investigated. The correlation coefficient (mean difference) using color Doppler M-mode imaging was 0.68 (85 ml). The corresponding values in functional mitral regurgitation were 0.74-0.88/0.74-0.88 (-5-8 ml/-7-5 ml) for two-dimensional color Doppler and 0.88 (-1 ml) for M-mode imaging. The regurgitant volume was overestimated by the proximal flow convergence method in organic mitral regurgitation irrespective of the application of different correction algorithms or the use of color Doppler M-mode. A sufficiently reliable determination of the regurgitant volume by the proximal flow convergence method was possible in functional mitral regurgitation. In that case a simplified calculation of the regurgitant volume based on the proximal flow convergence method was feasible.

Reproducibility of the proximal flow convergence method in mitral and tricuspid regurgitation

Background The follow-up of patients with mitral and tricuspid regurgitation is important for their clinical treatment. We aimed to evaluate the reproducibility of the flow convergence method in mitral and tricuspid regurgitation. Methods The proximal flow convergence region was imaged with color Doppler ultrasound scanning echocardiography in 83 patients with mitral regurgitation, tricuspid regurgitation, or both. Proximal isovelocity surface area radii for aliasing velocities of 27 to 29 cm/s and 41 to 43 cm/s were repeatedly measured by the same experienced investigator on different days and by experienced and less experienced investigators at 1 day. Results In mitral regurgitation, the intraobserver variability rate was 0.2% ± 13.5% (2.8% ± 13.3%) and the interobserver variability was 0.1% ± 13.8% (1.7% ± 18.0%) for an aliasing velocity of 27 to 29 cm/s (41–43 cm/s). For the aliasing velocity of 27 to 29 cm/s (41–43 cm/s), the 95% ranges for change of the proximal isovelocity surface area radii were ± 2.7 mm (± 1.8 mm) for measurements repeated by the same investigator and ± 2.7 mm (± 2.4 mm) for different investigators. Interobserver variability was independent of the investigators' experience. Similar data were achieved in tricuspid regurgitation. Conclusions The proximal flow convergence method is acceptably reproducible in mitral and tricuspid regurgitation independent of the investigators experience. For the aliasing velocity of 27 to 29 cm/s (41–43 cm/s), the proximal isovelocity surface area radius has to change for >2.7 (2.4) mm before an altered severity of mitral or tricuspid regurgitation in a single patient can be assumed.

Recommendations for evaluation of the severity of native valvular regurgitation with two-dimensional and doppler echocardiography

Recommendations for evaluation of the severity of native valvular regurgitation with two-dimensional and doppler echocardiography

Clinical application in routine practice of the proximal flow convergence method to calculate the mitral surface area in mitral valve stenosis.

Two-dimensional (2D) echocardiography planimetry, the Doppler pression half-time (PHT), and the continuity equation methods were used to estimate mitral valve area (MVA) in patients with mitral stenosis (MS). Recently, the proximal isovelocity surface area (PISA) method has been shown to be accurate for calculating MVA. The purpose of this study is (1) to compare in a large non-selected population the accuracy of the PISA and planimetry methods for echocardiographic estimation of MVA; (2) to determine the effect of atrial fibrillation (AF), Wilkins score, associated mitral regurgitation (MR), aortic regurgitation (AR), and of commissural calcifications on the accuracy of the PISA method. One hundred and eight consecutive patients with rheumatic MS were studied (76 females and 32 males; mean age: 36 +/- 12 years); 64 were in sinus rhythm; 51 had associated MR and 46 had AR. By the PISA method. MVA was calculated assuming a uniform radius flow convergence region along a hemispherical surface. The mean value of 2D MVA was 1.32 +/- 0.59 cm2 (0.4-3.1 cm2) and that of PISA MVA 1.33 +/- 0.62 cm2 (0.38-3 cm2). MVA calculated using the PISA method correlated well with 2D MVA (r = 0.93, y = 0.97x + 0.04, p < 0.0001, SEE = 0.21 cm2). The correlation was also good in patients with AF (r = 0.93, y = 0.99x + 0.03, p < 0.0001, SEE = 0.21 cm2), with MR (r = 0.94, y = 1.0 14x + 0.003, p < 0.0001, SEE = 0.19 cm2), with AR (r = 0.93, y = 0.90x + 0.11, p < 0.0001, SEE = 0.2 cm2), when Wilkins score was >8 (r = 0.92, = 0.96x + 0.06, p < 0.0001, SEE = 0.19 cm2), and in patients with commissural calcifications (r = 0.90, y = 0.88x + 0.009, p < 0.0001, SEE = 0.20 cm2). Our study shows that in routine practice, MVA calculated by the PISA method correlated well with the area obtained by planimetry even in the presence of commissural calcifications, associated MR, AR, AF and of high Wilkins score. Therefore, the PISA method provides a reliable measurement of the MVA in MS under different anatomic and clinical conditions and may be a useful alternative method for calculating MVA.