Jackie S. McGhie

Clinical value of real-time three-dimensional echocardiography for right ventricular quantification in congenital heart disease: validation with cardiac magnetic resonance imaging.

BACKGROUND The objective of this study was to test the feasibility, accuracy, and reproducibility of the assessment of right ventricular (RV) volumes and ejection fraction (EF) using real-time three-dimensional echocardiographic (RT3DE) imaging in patients with congenital heart disease (CHD), using cardiac magnetic resonance (CMR) as a reference. METHODS RT3DE data sets and short-axis cine CMR images were obtained in 62 consecutive patients (mean age, 26.9 +/- 10.4 years; 65% men) with various CHDs. RV volumetric quantification was done using semiautomated 3-dimensional border detection for RT3DE images and manual tracing of contours in multiple slices for CMR images. RESULTS Adequate RV RT3DE data sets could be analyzed in 50 of 62 patients (81%). The time needed for RV acquisition and analysis was less for RT3DE imaging than for CMR (P < .001). Compared with CMR, RT3DE imaging underestimated RV end-diastolic and end-systolic volumes and EF by 34 +/- 65 mL, 11 +/- 55 mL, and 4 +/- 13% (P < .05) with 95% limits of agreement of +/-131 mL, +/-109 mL, and +/-27%, as shown by Bland-Altman analyses, with highly significant correlations (r = 0.93, r = 0.91, and r = 0.74, respectively, P < .001). Interobserver variability was 1 +/- 15%, 6 +/- 17%, and 8 +/- 13% for end-diastolic and end-systolic volumes and EF, respectively. CONCLUSION In the majority of unselected patients with complex CHD, RT3DE imaging provides a fast and reproducible assessment of RV volumes and EF with fair to good accuracy compared with CMR reference data when using current commercially available hardware and software. Further studies are warranted to confirm our data in similar and other patient populations to establish its use in clinical practice.

Right ventricular quantification in clinical practice: two-dimensional vs. three-dimensional echocardiography compared with cardiac magnetic resonance imaging.

AIMS To establish the additional value of three-dimensional echocardiography (3D echo) for assessment of right ventricular (RV) size and function in patients with congenital heart disease (CHD) in everyday clinical practice, the accuracy and reproducibility of 3D echo were compared with conventional two-dimensional echocardiography (2D echo) and cardiac magnetic resonance (CMR) imaging as reference. METHODS AND RESULTS Patients with CHD and primarily affected right ventricles (n = 62), patients with CHD and primarily affected left ventricles (LV group, n = 27), and healthy controls (n = 31) were studied. 2D echo-, 3D echo- and CMR data sets were obtained. Moderate correlations were found between RV dimensions by 2D echo and CMR-derived RV end-diastolic volumes (r = 0.32-0.77). The correlations between RV volumes obtained by 3D echo and CMR imaging were better (r = 0.71-0.97) than the 2D echo-derived correlations (P < 0.001). Only the 2D echo-derived RV inlet diameter correlated better in healthy controls than in the RV group. Receiver operating characteristic curve analysis revealed that 3D echo-derived end-diastolic volume best identified RV dysfunction (sensitivity 95% and specificity 100%). The 3D echo-derived measurements were as reproducible as the 2D echo-derived measurements (n = 37, coefficients of variation ranging from 5 to 19%), with tricuspid annular plane systolic excursion being the most reproducible measurement (coefficient of variation of 6%). CONCLUSION 3D echo improved quantitative RV size and function assessment compared with 2D echo in patients as well as in healthy controls. Everyday clinical use of 3D echo for RV assessment can be reality with the currently available software and provides incremental benefit in assessment of the right ventricle.

Transthoracic three-dimensional echocardiography in adult patients with congenital heart disease

OBJECTIVES This study sought to assess both the feasibility and potential role of transthoracic three-dimensional echocardiography for the evaluation of adult patients with congenital heart disease. BACKGROUND The unrestricted views with depth perception provided by three-dimensional echocardiography with dynamic volume-rendered display may enhance visualization of cardiac structures and detection of abnormalities in patients with congenital heart defects. METHODS We studied 33 patients with various heart defects (mitral valve anomalies in 9, aortic valve anomalies in 5, subaortic membrane in 5, ventricular septal defect in 4, transposition of the great arteries in 3, tetralogy of Fallot in 2, other defects in 5). Cross-sectional images of the specific region of interest were acquired from either the parasternal or apical window with the rotational technique (2 degrees interval with electrocardiographic and respiratory gating) and postprocessed for resampling in cubic format. From these three-dimensional data sets a multitude of cut planes were selected, presented in volume-rendered dynamic display and analyzed by two observers for comparison with standard two-dimensional images to assess their additional information. RESULTS Three-dimensional reconstruction was possible in all patients. Structures of interest were evaluated from unusual viewpoints, providing both cardiologists and surgeons with immediate feedback. When compared with standard two-dimensional images, additional information was provided for 12 patients (36%). The mitral valve, aortoseptal continuity and interatrial septum were the structures for which three-dimensional echocardiography was most useful. CONCLUSIONS Transthoracic three-dimensional echocardiography is feasible and facilitates spatial recognition of the intracardiac anatomy in a significant proportion of patients and enhances diagnostic confidence of complex congenital heart disease.

Anatomy of the Mitral Valvular Complex and Its Implications for Transcatheter Interventions for Mitral Regurgitation

Mitral regurgitation (MR) poses a significant clinical burden in the adult population, which is expected to increase even more with the ever prolonging life expectancies in developed countries. New technology has brought MR, once exclusively the arena of cardiac surgeons, to the attention of interventional cardiologists. A variety of device-oriented transcatheter strategies have evolved in recent years. A comprehensive understanding of mitral valvular anatomy is crucial for the selection of patients, the implementation of devices, and further refinements of these transcatheter techniques if they are eventually to produce procedural and clinical success. The aim of this review is to elucidate the morphology of the mitral valvular complex, integrating key anatomical features into the developing transcatheter options for the treatment of MR.

Pulmonary wedge injections yielding left-sided echocardiographic contrast.

Ultrasound contrast on the left side of the heart without the need for left heart catheterisation was achieved by hand injections of 8 to 10 ml 5 per cent dextrose solution through a catheter in the pulmonary wedge position. Injections were performed in 18 patients undergoing routine cardiac catheterisation and M-mode or two-dimensional echocardiography was used. An adequate wedge position was attained in 17 of the 18 patients. Nine had injections through Cournand catheters, three through Swan-Ganz catheters, and five through both. In 11 of these 17 patients left atrial or left ventricular echocardiographic contrast was seen immediately after wedge injection. Two patients showed diminished or absent contrast on later injections from the same position. Better results were obtained with the Cournand catheter (11/15 positive) than with the Swan-Ganz (1/8 positive) catheter. Pulmonary artery injections proximal to the wedge position did not cause left-sided contrast. No complications were observed. The safety of this method remains to be determined.

Use of three-dimensional echocardiography for analysis of outflow obstruction in congenital heart disease

To evaluate the feasibility and accuracy of 3-dimensional (3D) echocardiography in analysis of left and right ventricular outflow tract (LVOT and RVOT) obstruction, 3D echocardiography was performed in 28 patients (age 4 months to 36 years) with outflow tract pathology. Type of lesion and relation to valves were assessed. Length and degree of obstruction were measured. Three-D data sets were adequate for reconstruction in 25 of 28 patients; 47 reconstructions were made. In 13 patients with LVOT obstruction, 3D echocardiography was used to study subvalvular details in 8, valvular in 13, and supravalvular in 1. Four of these 13 patients had complex subaortic obstruction. In 12 patients with RVOT lesions, 3D echocardiography was used to study subvalvular details in 11, valvular in 12, and supravalvular in 2. Three-dimensional reconstructions were suitable for analysis in 100% of subvalvular LVOT, 77% valvular LVOT, 100% supravalvular LVOT, 100% subvalvular RVOT, 50% valvular RVOT, and 50% supravalvular RVOT. Twenty patients underwent operation, and surgical findings served as morphologic control for thirty-four 3D reconstructions (LVOT 17, RVOT 17). Operative findings revealed an accuracy at subvalvular LVOT of 100%, valvular LVOT 90%, supravalvular LVOT 100%, subvalvular RVOT 100%, valvular RVOT 100%, and supravalvular RVOT 100%. Quantitative measurements could adequately be performed. Three-D echocardiography is feasible and accurate for analyzing both outflow tracts of the heart. Particularly, generation of nonconventional horizontal cross sections allows a good definition of extension and severity of lesions.

A Simplified Continuity Equation Approach to the Quantification of Stenotic Bicuspid Aortic Valves using Velocity-Encoded Cardiovascular Magnetic Resonance

OBJECTIVE We aimed to compare velocity-encoded cine cardiac magnetic resonance (CMR) with an established echocardiographic method for noninvasive measurement of aortic valve area (AVA) using the continuity equation. METHODS AND RESULTS Twenty consecutive young adults with stenotic bicuspid aortic valves were examined with CMR and transthoracic echocardiography (TTE). CMR AVA was calculated by the continuity equation, dividing stroke volume by the aortic velocity-time integral (VTIAorta), the stroke volume measured both by ventricular volume analysis and by phase contrast velocity mapping at 4 levels (1 subvalvar and 3 supravalvar). Stroke volumes measured at all levels correlated well with those from volumetric analysis. The CMR AVAs calculated using volumetric analysis and VTIAorta from jet velocity mapping correlated and agreed well with TTE AVA measurements (R2 = 0.83). When CMR AVA was calculated more rapidly using volume flow and VTIAorta both measured from the same trans-jet velocity acquisition, R2 was 0.74, with a bias and limits of agreement of 0.02 (-0.44, 0.47) cm2. CONCLUSIONS Continuity equation calculation of the AVA using CMR velocity mapping, with or without ventricular volumetric measurement, correlated and agreed well with the comparable and widely accepted TTE approach.

Usefulness of real-time three-dimensional echocardiography to identify right ventricular dysfunction in patients with congenital heart disease.

Because right ventricular (RV) dysfunction predicts a poor outcome in patients with congenital heart disease (CHD), regular monitoring of RV function is indicated. To date, cardiac magnetic resonance (CMR) imaging has been the reference method. A more practical, more accessible, and accurate tool would be preferred. We defined normality regarding RV systolic function using healthy controls and tested the ability of real-time 3-dimensional echocardiographic (RT3DE) findings to identify patients with CHD with RV dysfunction. The cutoff values for the RV volumes and ejection fraction (EF) were derived from the CMR imaging findings from 41 healthy controls (mean age 27 +/- 8 years, 56% men). In 100 patients with varying CHDs (mean age 27 +/- 11 years, 65% men), both RT3DE data sets (iE33) and short-axis CMR imaging (1.5 T) were obtained within 2 hours. The RT3DE and CMR RV volumes and EF were calculated using commercially available software. Receiver operating characteristic curves were created to obtain the sensitivity and specificity of the RT3DE data to identify RV dysfunction. Applying the cutoff values derived from the healthy controls using the CMR data of patients with CHD, we identified 23 patients with an enlarged indexed end-diastolic volume, 29 patients with an enlarged indexed end-systolic volume, and 21 patients with an impaired RVEF. The best cutoff values predicting RV dysfunction using the RT3DE findings were identified (indexed end-diastolic volume >105 ml/m(2), indexed end-systolic volume >54 ml/m(2), and EF <43%). The RT3DE findings revealed 23 patients with impaired RVEF, with 95% sensitivity, 89% specificity, and a negative predictive value of 99%. In conclusion, real-time 3-dimensional echocardiography is a very sensitive tool to identify RV dysfunction in patients with CHD and could be applied clinically to rule out RV dysfunction or to indicate additional quantitative analysis of RV function.

Consequences of a selective approach toward pulmonary valve replacement in adult patients with tetralogy of Fallot and pulmonary regurgitation.

OBJECTIVE The aim of the study was to assess the long-term results of a selective policy toward pulmonary valve replacement in adult patients with repaired tetralogy of Fallot and severe pulmonary regurgitation. METHODS Sixty-seven patients with tetralogy of Fallot were followed up from 15 +/- 3 years until 27 +/- 3 years after surgery. RESULTS Twenty-two patients had mild-to-moderate pulmonary regurgitation. No significant changes occurred in the follow-up period. Of 45 patients with severe pulmonary regurgitation and severe right ventricular dilatation, 28 (62%) remained free of symptoms and did not undergo pulmonary valve replacement. No changes in right ventricular size or exercise capacity were found. In 3 (11%) of 28 patients, QRS duration increased to more than 180 ms. Seventeen patients had symptoms and underwent pulmonary valve replacement: 9 (54%) of 17 patients improved clinically and echocardiographically, and QRS duration shortened postoperatively. Right ventricular dimensions did not regress despite pulmonary valve replacement in 8 patients. CONCLUSION Refraining from pulmonary valve replacement in asymptomatic patients led to no measurable deterioration in 25 (89%) of 28 patients. Referring symptomatic patients for pulmonary valve replacement led to an improvement in 9 (53%) of 17 patients. In 11 (24%) of 45, a selective approach led to questionable or unsatisfactory results.

THREE-DIMENSIONAL ECHOCARDIOGRAPHY ENHANCES THE ASSESSMENT OF VENTRICULAR SEPTAL DEFECT

By 3-dimensional echocardiography, the location, relation to the aortic and tricuspid valve, and the size of the ventricular septal defect was assessed and compared with 2-dimensional echocardiography and intraoperative findings. We concluded that 3-dimensional echocardiography accurately assesses the anatomy of the ventricular septal defect, provides additional information, and can be considered a valuable preoperative diagnostic tool.