Quantification of mitral regurgitation by live three-dimensional transthoracic echocardiographic measurements of vena contracta area

We evaluated 44 consecutive patients who underwent standard two-dimensional (2D) and live three-dimensional (3D) transthoracic echocardiography (TTE), as well as left heart catheterization with left ventriculography. Mitral regurgitant vena contracta area (VCA) was obtained by 3D TTE by systematic and sequential cropping of the acquired 3D TTE data set. Assessment of mitral regurgitation (MR) by ventriculography was compared to measurements of VCA by 3D TTE and to 2D TTE measurements of MR jet area to left atrial area (RJA/LAA), RJA alone, vena contracta width (VCW), and calculated VCA. VCA from 3D TTE closely correlated with angiographic grading (rs=0.88) with very little overlap. VCA of <0.2 cm2 correlated with mild MR, 0.2-0.4 cm2 with moderate MR, and >0.4 cm2 with severe MR by angiography. Ventriculographic grading also correlated well with 2D TTE measurements of RJA/LAA (rs=0.79) and RJA alone (rs=0.76) but with more overlap. Assessment of VCW and calculated VCA by 2D TTE agreed least with ventriculography (rs=0.51 and rs=0.55, respectively). Live 3D TTE color Doppler measurements of VCA can be used for quantitative assessment of MR and is comparable to assessment by ventriculography.     

Assessment of aortic regurgitation by live three-dimensional transthoracic echocardiographic measurements of vena contracta area: usefulness and validation

In this report, we evaluate 56 consecutive adult patients who underwent standard two-dimensional (2D) and live three-dimensional transthoracic echocardiography (3D TTE), as well as left heart catheterization with aortography (45 patients) or cardiac surgery (11 patients), for evaluation of aortic insufficiency. Similar to the method we previously described for mitral insufficiency, aortic regurgitant vena contracta area (VCA) was obtained by 3D TTE by systematic and sequential cropping of the acquired 3D TTE data set. Assessments of aortic regurgitation (AR) by aortography and surgery are compared to measurements of VCA by 3D TTE and to 2D TTE measurements of vena contracta width (VCW). Aortographic or surgical grading correlated well with 2D TTE measurements of VCW (r = 0.92), but correlated better with 3D TTE measurements of VCA (r = 0.95), with improved dispersion between angiographic grades demonstrated by the 3D TTE technique. Live 3D TTE color Doppler measurements of VCA can be used for accurate assessment of AR and are comparable to assessment by aortography.     

Live/real time three-dimensional transthoracic echocardiographic assessment of pulmonary regurgitation

There is no gold standard for the measurement of pulmonary regurgitation (PR) severity. Two-dimensional (2D) transthoracic echocardiography is most commonly used to quantify PR severity using color Doppler criteria for aortic regurgitation. However, this method is limited by visualization of only one or two dimensions of the proximal PR jet or vena contracta (VC) precluding accurate assessment of its shape or size. This limitation would be expected to be obviated by three-dimensional (3D) transthoracic echocardiography, which could provide a more accurate quantitative assessment of PR severity. This study evaluated 82 adult patients with PR using 2D and 3D. PR VC area by 3D was obtained by planimetry by positioning the cropping plane exactly parallel to the VC, which was viewed en face by cropping of the 3D data set. Regurgitant volumes were calculated by 2D (assuming a circular VC) and by 3D as a product of the VC and velocity time integral obtained by color Doppler-guided conventional Doppler interrogation of the PR jet.The 3D VC area correlated with 2D jet width (JW)/right ventricular outflow tract (RVOT) width (r = 0.71) and 2D VC area (r = 0.79). 3D JW/RVOT width correlated with 2D JW/RVOT (r = 0.87). 3D regurgitant volumes also correlated with 2D regurgitant volumes (r = 0.76). The 3D VC values of <0.20, 0.20-0.45, 0.46-1.15, and >1.15 cm(2) and regurgitant volumes of <15 ml, 15-50 ml, 51-115 ml, and >115 ml were effective as cutoffs for grades 1, 2, 3, and 4 PR, respectively. In conclusion, quantification of 3D VC area and regurgitant volumes correlate reasonably well with the current 2D methods for measurement of PR. Since 3D visualizes PR VC in three dimensions, it would be expected to provide a more accurate and more quantitative assessment of PR severity as compared to 2D.     

Traumatic tricuspid papillary muscle and chordae rupture: emerging role of three-dimensional echocardiography

We describe a patient with blunt traumatic chest injury in whom three-dimensional transthoracic echocardiography (3DTTE) confirmed the findings of a flail anterior tricuspid valve leaflet and ruptured anterior papillary muscle seen on two-dimensional transthoracic echocardiography, and in addition identified multiple chordae tendinae rupture of the posterior leaflet. Open heart surgery confirmed the findings. The emerging role of 3DTTE in defining the true extent of traumatic tricuspid valvular injury is highlighted .     

Comparison of intraoperative three-dimensional Doppler color flow mapping to assess mitral regurgitation

Background: Three-dimensional (3D) transesophageal echocardiography (TEE) enables the determination of the vena contracta area (VCA), which is an approved parameter to quantify mitral regurgitation (MR). The aim of this study was to determine the VCA in the operative setting and to compare it to alternative 3D and standard 2D methods, with respect to different etiologies of MR. Methods: MR in 56 consecutive patients undergoing cardiac surgery was evaluated using 2D and 3D TEE. VCA, vena contracta (VC), and effective regurgitation orifice area (EROA) by 3D and 2D flow convergence methods were determined. The correlations among the methods and the determined areas were evaluated. Results: EROA determination using 3D flow convergence areas correlated strongly with VCA (r = 0.653), however the resulting areas were considerably smaller. VC measurements in the 3D data set correlated slightly less (r = 0.629). EROA, which was determined using 2D flow convergence areas, showed the strongest correlation among the 2D methods (r = 0.406). 2D VC measurements showed weak to no correlation with VCA. Although a correlation was detected when using the biplane method or the midesophageal long-axis view to measure VC, statistical significance was only reached in functional MR and MR due to simple prolapse. Conclusions: Intraoperative 3D methods to determine MR were feasible and showed improved correlation with VCA compared to 2D measurements. The agreement of 2D methods with VCA declined from functional MR to MR due to prolapse. We recommend the utilization of 3D color Doppler for intraoperative evaluation of MR, especially in patients with complex mitral valve prolapses.     

Comparison of the proximal flow convergence method and the jet area method for the assessment of the severity of tricuspid regurgitation

Aims To compare the value of the proximal flow convergence methodand the jet area method for the determination of the severityof tricuspid regurgitation. Methods and Results The proximal isovelocity surface area radius and the jet area/lengthwere measured in 71 consecutive patients with angiographicallygraded (grade 0/I–III) tricuspid regurgitation. Rank correlationcoef-ficients with the angiographic grade were 0·71 (P<0·001)for the proximal isovelocity surface area radius (aliasing borderof 28cm.s^–1), 0·66 (P<0·001) for thejet area, and 0·63 (P<0·001) for the jet length.The proximal isovelocity surface area radius was significantlycorrelated with the jet area/length (correlation coefficients0·82/0·77, P<0·001). Correct differentiationbetween mild to moderate (grade I–II) and severe (gradeIII) tricuspid regurgitation was achieved in 62 of 71 patients(87%) by means of the proximal isovelocity surface area radius,in 61 of 71 (86%) by the jet area, and in 62 of 71 (87%) bythe jet length. Grade III tricuspid regurgitation was not identifiedin five of 21 patients (24%) by means of the proximal isovelocitysurface area radius, in six of 21 (29%) by the jet area, andin seven of 21 (33%) by the jet length. Conclusion The flow convergence method and the jet area method are of similarvalue for the determination of the severity of tricuspid regurgitation.Both methods differentiated mild to moderate from severe tricuspidregurgitation in most patients. However, underestimation ofsevere tricuspid regurgitation in 20–30% of the casesrepresents a serious limitation of both methods.     

Isolated rheumatic severe tricuspid regurgitation

Severe isolated tricuspid regurgitation (TR) is very rare, with most cases of TR being functional and secondary to pulmonary hypertension from left heart pathologies. We report an unusual case of a young Nigerian male, who presented to us with dyspnea, repeated hospital admissions for heart failure, and a childhood history of rheumatic fever. Echocardiogram showed massively dilated right atrium and ventricle, noncoaptation of thickened tricuspid valve with torrential free tricuspid regurgitation. Other valves were normal. Cardiac MRI showed normal right ventricular function and viability. Patient underwent tricuspid valve replacement with 35‐mm St. Jude valve.     

Live/real time three-dimensional transthoracic echocardiographic assessment of Ebstein's anomaly

We describe our experience in using live/real time three-dimensional transthoracic echocardiography (3D TTE) in the assessment of five adult patients with Ebstein's anomaly. The technique was found useful in assessing the distribution and extent of tethering of each of the three leaflets of the tricuspid valve (TV) to the underlying right ventricular walls and the ventricular septum. The characteristic bubble-like appearance resulting from bulging of the non-tethered areas of the TV leaflets was also well visualized in three dimensions and their size measured. Thus, an estimate of the nontethered or free segments of all three leaflets of the TV could be obtained using this technique. This has important implications when considering these patients for surgical repair of the TV. Visualization of all three leaflets of the TV and their extent of tethering by 3D TTE also made it easier to identify the boundaries of the functioning right ventricular chamber potentially providing a more reliable assessment of its volumes and ejection fraction. Cropping of color Doppler 3D TTE data sets provided en face viewing of the TV regurgitation vena contracta permitting accurate assessment of its shape and size. This has the potential to provide a more accurate quantitative estimation of TV regurgitation severity as compared to two-dimensional color Doppler. In conclusion, live/real time 3D TTE appears useful in supplementing two-dimensional echocardiography in more comprehensively assessing the morphologic features of Ebstein's anomaly.     

Transthoracic and transesophageal echocardiographic assessment of mitral regurgitation severity: usefulness of qualitative and semiquantitative techniques

In this report, we review the advantages, limitations, and optimal utilization of various transthoracic and transesophageal echocardiographic (TTE and TEE) methods used for assessing mitral regurgitation (MR) as published in full-length, peer-reviewed articles since the color Doppler era began in 1984. In addition, comparison is made to other imaging modalities including catheter-based, magnetic resonance and surgical assessment of MR. Although left ventricular (LV) angiography has been traditionally used for validation of various TTE methods and is time-honored, its considerable limitations preclude it from being a real "gold standard." Based on the reviewed literature, no clear "gold standard" for the assessment of MR can be identified at present, but newly emerging TTE and TEE techniques, such as three-dimensional color Doppler, may have the potential to overcome some of the limitations of the two-dimensional methods.     

Effects of changing blood viscosity and heart rate on vena contracta width as evaluated by color Doppler flow mapping. An in vitro study with a pulsatile flow model

BACKGROUND: There is only limited knowledge on how the quantification of valvular regurgitation by color Doppler is affected by changing blood viscosity. This study was designed to evaluate the effect of changing blood viscosity on the vena contracta width using an in vitro model of valvular insufficiency capable of providing ample variation in the rate and stroke volume. METHODS: We constructed a pulsatile flow model filled with human blood at varying hematocrit (15%, 35%, and 55%) and corresponding blood viscosity (blood/water viscosity: 2.6, 4.8, 9.1) levels in which jets were driven through a known orifice (7 mm2) into a 110 mL compliant receiving chamber (compliance: 2.2 mL/mmHg) by a pulsatile pump. In addition, we used variable pump stroke volumes (5, 7.5, and 10 mL) and rates (40, 60, and 80 ppm). Vena contracta region was imaged using a 3.5 MHz transducer. Pressure and volume in the flow model were kept constant during each experimental condition, as well as ultrasound settings. RESULTS: Blood viscosity variation in the experimental range did not induce significant changes in vena contracta dimensions. Also, vena contracta width did not change from normal to low hematocrit and viscosity levels. A very modest increase only in vena contracta dimension was observed at very high level of blood viscosity when hematocrit was set to 55% . Pump rate, in the evaluated range, did not influence vena contracta width. These results in controlled experimental settings suggest that the vena contracta is an accurate quantitative method for quantifying valvular regurgitation even when this condition is associated with anemia, a frequent finding in patients with valvular heart disease.     

Live three-dimensional transthoracic echocardiographic assessment of thrombus in the innominate veins and superior vena cava utilizing right parasternal and supraclavicular approaches

We report the usefulness of right parasternal and supraclavicular live three-dimensional transthoracic echocardiography in the delineation and follow-up of a thrombus involving a catheter placed in superior vena cava for dialysis in an adult patient with chronic renal disease.     

Severe tricuspid regurgitation due to entrapment of the anterior leaflet of the valve by a permanent pacemaker lead: role of real time three-dimensional echocardiography

Pacemaker leads may impair tricuspid valve coaptation and they are a well-known cause of mild tricuspid regurgitation. Occasionally, right ventricular leads worsen tricuspid regurgitation over time and patients develop late-onset symptoms of right-sided heart failure. The exact mechanism of this clinical entity is rarely identifiable by 2D-echocardiography only. This case report details a patient with severe tricuspid regurgitation secondary to immobilization of the anterior leaflet of the tricuspid valve by a permanent ventricular pacing lead. The mechanism of regurgitation was clarified by real time three-dimensional echocardiography that showed the location of the ventricular lead and its interference with the tricuspid valve.