Lanqi Hua

Geometric Determinants of Functional Tricuspid Regurgitation Insights From 3-Dimensional Echocardiography

Background— Tricuspid regurgitation (TR) is an important predictor of morbidity and mortality in heart failure. We aimed to examine the 3D geometry of the tricuspid valve annulus (TVA) in patients with functional TR, comparing them with patients with normal tricuspid valve function and relating annular geometric changes to functional TR. Methods and Results— TVA shape was examined by real-time 3D echocardiography in 75 patients: 35 with functional TR and 40 with normal tricuspid valve function (referent group). The 3D shape of the TVA was reconstructed from rotated 2D planes, and the annular plane was computed by least-squares fitting. Annular area and mediolateral, anteroposterior, and high (superior)-low (inferior) distances were calculated. TR was assessed by vena contracta width. The normal TVA has a bimodal pattern (high-low distance=7.23±1.05 mm). High points were located anteroposteriorly, and low points were located mediolaterally. With moderate or greater TR (vena contracta width 5.80±2.62 mm), the TVA became dilated (17.24±4.75 versus 9.83±2.18 cm2, P<0.0001, TR versus referent), more planar with decreased high-low distance (4.14±1.05 mm), and more circular with decreased ratio of mediolateral/anteroposterior (1.11±0.09 versus 1.32±0.09, P<0.0001, TR versus referent). Conclusions— The normal TVA has a bimodal shape with distinct high points located anteroposteriorly and low points located mediolaterally. With functional TR, the annulus becomes larger, more planar, and circular. These changes in annular shape with TR have potentially important mechanistic and therapeutic implications for tricuspid valve repair.

Guidelines for the Echocardiographic Assessment of the Right Heart in Adults: A Report from the American Society of Echocardiography

on Statement: Society of Echocardiography is accredited by the Accreditation Council for edical Education to provide continuing medical education for physicians. n Society of Echocardiography designates this educational activity for of 1.0 AMA PRA Category 1 Credits . Physicians should only claim credit te with the extent of their participation in the activity. CCI recognize ASE’s certificates and have agreed to honor the credit hours registry requirements for sonographers. Society of Echocardiography is committed to ensuring that its educational ll sponsored educational programs are not influenced by the special interests ation or individual, and its mandate is to retain only those authors whose fists can be effectively resolved to maintain the goals andeducational integrity y. While a monetary or professional affiliation with a corporation does not fluence an author’s presentation, the Essential Areas and policies of the ire that any relationships that could possibly conflict with the educational activity be resolved prior to publication and disclosed to the audience. f faculty and commercial support relationships, if any, have been indicated. ience: is designed for all cardiovascular physicians and cardiac sonographers with erest and knowledge base in the field of echocardiography; in addition, reschers, clinicians, intensivists, and other medical professionals with a spein cardiac ultrasound will find this activity beneficial.

Mitral Leaflet Adaptation to Ventricular Remodeling Occurrence and Adequacy in Patients With Functional Mitral Regurgitation

Background— Functional mitral regurgitation (MR) is caused by systolic traction on the mitral leaflets related to ventricular distortion. Little is known about whether chronic tethering causes the mitral leaflet area to adapt to the geometric needs imposed by tethering, in part because of inability to reconstruct leaflet area in vivo. Our aim was to explore whether adaptive increases in leaflet area occur in patients with functional MR compared with normal subjects and to test the hypothesis that leaflet area influences MR severity. Methods and Results— A new method for 3-dimensional echocardiographic measurement of mitral leaflet area was developed and validated in vivo against 15 sheep heart valves, later excised. This method was then applied in 80 consecutive patients from 3 groups: patients with normal hearts by echocardiography (n=20), patients with functional MR caused by isolated inferior wall-motion abnormality or dilated cardiomyopathy (n=29), and patients with inferior wall-motion abnormality or dilated cardiomyopathy but no MR (n=31). Leaflet area was increased by 35±20% in patients with LV dysfunction compared with normal subjects. The ratio of leaflet to annular area was 1.95±0.40 and was not different among groups, which indicates a surplus leaflet area that adapts to left-heart changes. In contrast, the ratio of total leaflet area to the area required to close the orifice in midsystole was decreased in patients with functional MR compared with those with normal hearts (1.29±0.15 versus 1.78±0.39, P=0.001) and compared with patients with inferior wall-motion abnormality or dilated cardiomyopathy but no MR (1.81±0.38, P=0.001). After adjustment for measures of LV remodeling and tethering, a leaflet-to-closure area ratio <1.7 was associated with significant MR (odds ratio 23.2, 95% confidence interval 2.0 to 49.1, P=0.02). Conclusions— Mitral leaflet area increases in response to chronic tethering in patients with inferior wall-motion abnormality and dilated cardiomyopathy, but the development of significant MR is associated with insufficient leaflet area relative to that demanded by tethering geometry. The varying adequacy of leaflet adaptation may explain in part the heterogeneity of this disease among patients. The results suggest the need to understand the mechanisms that underlie leaflet adaptation and whether leaflet area can potentially be modified as part of the therapeutic approach.

Diagnostic Value of Vena Contracta Area in the Quantification of Mitral Regurgitation Severity by Color Doppler 3D Echocardiography

Background— Accurate quantification of mitral regurgitation (MR) is important for patient treatment and prognosis. Three-dimensional echocardiography allows for the direct measure of the regurgitant orifice area (ROA) by 3D-guided planimetry of the vena contracta area (VCA). We aimed to (1) establish 3D VCA ranges and cutoff values for MR grading, using the American Society of Echocardiography–recommended 2D integrative method as a reference, and (2) compare 2D and 3D methods of ROA to establish a common calibration for MR grading. Methods and Results— Eighty-three patients with at least mild MR underwent 2D and 3D echocardiography. Direct planimetry of VCA was performed by 3D echocardiography. Two-dimensional quantification of MR included 2D ROA by proximal isovelocity surface area (PISA) method, vena contracta width, and ratio of jet area to left atrial area. There were significant differences in 3D VCA among patients with different MR grades. As assessed by receiver operating characteristic analysis, 3D VCA at a best cutoff value of 0.41 cm2 yielded 97% of sensitivity and 82% of specificity to differentiate moderate from severe MR. There was significant difference between 2D ROA and 3D VCA in patients with functional MR, resulting in an underestimation of ROA by 2D PISA method by 27% as compared with 3D VCA. Multivariable regression analysis showed functional MR as etiology was the only predictor of underestimation of ROA by the 2D PISA method. Conclusions— Three-dimensional VCA provides a single, directly visualized, and reliable measurement of ROA, which classifies MR severity comparable to current clinical practice using the American Society of Echocardiography–recommended 2D integrative method. The 3D VCA method improves accuracy of MR grading compared with the 2D PISA method by eliminating geometric and flow assumptions, allowing for uniform clinical grading cutoffs and ranges that apply regardless of etiology and orifice shape.

Leaflet Area as a Determinant of Tricuspid Regurgitation Severity in Patients with Pulmonary Hypertension

Background—Tricuspid regurgitation (TR) is a risk factor for mortality in pulmonary hypertension (PH). TR severity varies among patients with comparable degrees of PH and right ventricular remodeling. The contribution of leaflet adaptation to the pathophysiology of TR has yet to be examined. We hypothesized that tricuspid leaflet area (TLA) is increased in PH, and that the adequacy of this increase relative to right ventricular remodeling determines TR severity. Methods and Results—A prospective cohort of 255 patients with PH from pre and postcapillary pathogeneses was assembled from 2 centers. Patients underwent a 3-dimensional echocardiogram focused on the tricuspid apparatus. TLA was measured with the Omni 4D software package. Compared with normal controls, patients with PH had a 2-fold increase in right ventricular volumes, 62% increase in annular area, and 49% increase in TLA. Those with severe TR demonstrated inadequate increase in TLA relative to the closure area, such that the ratio of TLA:closure area <1.78 was highly predictive of severe TR (odds ratio, 68.7; 95% confidence interval, 16.2–292.7). The median vena contracta width was 8.5 mm in the group with small TLA and large closure area as opposed to 4.8 mm in the group with large TLA and large closure area. Conclusions—TLA plays a significant role in determining which patients with PH develop severe functional TR. The ratio of TLA:closure area, reflecting the balance between leaflet adaptation versus annular dilation and tethering forces, is an indicator of TR severity that may identify which patients stand to benefit from leaflet augmentation during tricuspid valve repair.

Assessment of Image Quality in Real Time Three-Dimensional Dobutamine Stress Echocardiography: An Integrated 2D/3D Approach

Three‐dimensional (3D) stress echocardiography is a relatively new technique offering the potential to acquire images of the entire left ventricle from 1 or 2 transducer positions in a time‐efficient manner. Relative to two‐dimensional (2D) imaging, the ability to quickly acquire full volume images during peak stress with 3D echocardiography can eliminate left ventricular (LV) foreshortening while reducing inter‐operator variability. Our objectives were to (1) determine the practicality of a novel integrated 2D/3D stress protocol in incorporating 3D imaging into a standard 2D stress echocardiogram and (2) to determine whether the quality of imaging using the novel 2D/3D protocol was sufficient for interpretation.

Unusual Position of a Prosthetic Mitral Valve

Extensive calcification of the mitral annulus in patients who require mitral valvereplacement presents a significant challenge to the surgeon. Several techniques, includingdebridement of the calcium, reconstruction of the annulus, and insertion of the prosthesis in a locationother than the annulus, have been used in such patients. We report the echocardiographictechniques used to evaluate the case of a woman with an unusually positioned prosthetic mitralvalve.