Diagnostic Value of Aortic Valve Calcification Levels in the Assessment of Low-Gradient Aortic Stenosis.

BACKGROUND: In patients with low-gradient aortic stenosis (AS) and low transvalvular flow, dobutamine stress echocardiography (DSE) is recommended to determine AS severity, whereas the degree of aortic valve calcification (AVC) supposedly correlates with AS severity according to current European and American guidelines. OBJECTIVES: The purpose of this study was to assess the relationship between AVC and AS severity as determined using echocardiography and DSE in patients with aortic valve area <1 cm2 and peak aortic valve velocity <4.0 m/s. METHODS: All patients underwent DSE to determine AS severity and multislice computed tomography to quantify AVC. Receiver-operating characteristics curve analysis was used to assess the diagnostic value of AVC for AS severity grading as determined using echocardiography and DSE in men and women. RESULTS: A total of 214 patients were included. Median age was 78 years (25th-75th percentile: 71-84 years) and 25% were women. Left ventricular ejection fraction was reduced (<50%) in 197 (92.1%) patients. Severe AS was diagnosed in 106 patients (49.5%). Moderate AS was diagnosed in 108 patients (50.5%; in 77 based on resting transthoracic echocardiography, in 31 confirmed using DSE). AVC score was high (≥2,000 for men or ≥1,200 for women) in 47 (44.3%) patients with severe AS and in 47 (43.5%) patients with moderate AS. AVC sensitivity was 44.3%, specificity was 56.5%, and positive and negative predictive values for severe AS were 50.0% and 50.8%, respectively. Area under the receiver-operating characteristics curve was 0.508 for men and 0.524 for women. CONCLUSIONS: Multi-slice computed tomography-derived AVC scores showed poor discrimination between grades of AS severity using DSE and cannot replace DSE in the diagnostic work-up of low-gradient severe AS.

Repeated Echocardiograms Do Not Provide Incremental Prognostic Value to Single Echocardiographic Assessment in Minimally Symptomatic Patients with Chronic Heart Failure: Results of the Bio-SHiFT Study.

BACKGROUND: We aimed to compare the prognostic value of a single "baseline" echocardiogram with repeated echocardiography in stable chronic heart failure (CHF) patients. We hypothesized that repeated echocardiograms would contain incremental prognostic information. METHODS: In the prospective Bio-SHiFT study, we performed 332 echocardiograms in 106 patients during a median follow-up of 2.3 years. The endpoint comprised HF hospitalization, left ventricular (LV) assist device implantation, heart transplantation, and cardiovascular death. We compared hazard ratios (HRs; adjusted for N-terminal pro-brain natriuretic peptide) from Cox models for the first available measurement with HRs from joint models, which model individual trajectories based on the repeated measurements and link these to the time-to-event data. RESULTS: The mean age of the patients was 58.1 years; 78.3% were male, 12.6% had New York Heart Association class >II, all had reduced ejection fraction, and the most common HF etiologies were cardiomyopathies (51%) and ischemia (40%). The endpoint occurred in 25 patients. Both the single measurements and the temporal trajectories were significantly associated with the endpoint (adjusted HR Cox model [95% CI] vs adjusted HR joint model [95% CI]): LV ejection fraction, 1.47 (0.93-2.31) vs 1.77 (1.13-2.93); diastolic LV diameter, 1.64 (1.09-2.47) vs 1.68 (1.12-2.57); systolic LV diameter, 1.72 (1.10-2.69) vs 1.68 (1.13-2.63); systolic left atrial diameter, 1.88 (1.18-3.00) vs 2.60 (1.48-4.97); E/A ratio, 2.73 (1.42-5.26) vs 3.87 (1.75-10.13); and E/e' ratio, 2.30 (1.38-3.84) vs 2.99 (1.68-6.19). None of the trajectories from the investigated parameters showed worsening prior to events. CONCLUSIONS: Although single baseline or repeatedly measured echocardiographic parameters were associated with the endpoint, all parameters remained on average stable during the 2.3 years of follow-up in this largely minimally symptomatic CHF cohort. Thus, regular echocardiographic monitoring of systolic or diastolic LV function within this time frame does not carry incremental prognostic information over a single baseline measurement.

Accuracy of an automated transthoracic echocardiographic tool for 3D assessment of left heart chamber volumes.

AIMS: The feasibility and accuracy of an automated adaptive algorithm (Heart Model) for the quantification of left heart chamber volumes and left ventricular ejection fraction has been reported earlier. An improved version of the algorithm is available, and we aimed to test its accuracy compared with manual 3D echocardiography. METHODS AND RESULTS: Apical 3D transthoracic datasets were obtained in 67 patients. Acquisitions covering ventricles and atria were performed for analysis using the automated software (Heart Model, Philips Healthcare). In addition, acquisitions focused on the left ventricle were acquired for left ventricle manual 3D measurements (QLAB 10 3DQA, Philips Healthcare). Automated results using endocardial contouring settings at 50% showed a strong correlation with manual 3D measurements (r=.84-.97). Left ventricular end-diastolic volumes were underestimated (bias -5.9 mL, LOA ±38.5 mL), with no significant differences in other parameters. Intra-observer variability using the automated algorithm was zero for all parameters given the lack of human interaction. Manual corrections of the automatic algorithm introduced small but significant differences in volumes but not in ejection fraction when compared with automatic results. Manually corrected results of the automatic algorithm were not significantly different from those obtained with manual 3D echocardiography, except for a small underestimation of left atrial volumes (bias -2.1 mL, LOA ±15.2 mL). CONCLUSIONS: The current improved version of the automated adaptive algorithm is accurate for the assessment of left heart chamber volumes, albeit a small underestimation of left ventricular end-diastolic volume is seen, when compared with manual 3D echocardiography.

The Role of Automated 3D Echocardiography for Left Ventricular Ejection Fraction Assessment.

Ejection fraction is one of the most powerful determinants of prognosis and is a crucial parameter for the determination of cardiovascular therapies in conditions such as heart failure, valvular conditions and ischaemic heart disease. Among echocardiographic methods, 3D echocardiography has been attributed as the preferred one for its assessment, given an increased accuracy and reproducibility. Full-volume multi-beat acquisitions are prone to stitching artefacts due to arrhythmias and require prolonged breath holds. Single-beat acquisitions exhibit a lower temporal resolution, but address the limitations of multi-beat acquisitions. If not fully automated, 3D echocardiography remains time-consuming and resource-intensive, with suboptimal observer variability, preventing its implementation in routine practice. Further developments in hardware and software, including fully automated knowledge-based algorithms for left ventricular quantification, may bring 3D echocardiography to a definite turning point.

Quantitative assessment of the entire right ventricle from one acoustic window: an attractive approach.

AIMS: The aim of this prospective study was to evaluate the feasibility and establish normal values of functional right ventricle (RV) parameters as assessed in our four, long-axis view RV model using iRotate echocardiography. Furthermore, we evaluated the potential use of this model in patients with abnormally loaded RVs. METHOD AND RESULTS: One hundred and fifty-five healthy subjects aged 20-72 years (≥28 subjects per decile) were prospectively recruited. We used non-dedicated RV speckle-tracking software to test the feasibility and to establish normal range values of peak systolic global longitudinal RV strain (RV-GLS) from the RV free-walls (septum was excluded). Also normal range values for: dimensions, tricuspid annular plane systolic excursion (TAPSE) and tricuspid annular peak systolic velocity (TDI-S') were established. The feasibility of RV-GLS was 88, 84, and 62%, respectively, in the lateral, inferior, and anterior free wall. Mean RV-GLS normal values were -24.5 ± 4.9% for lateral wall and -25.4 ± 5.0% for anterior wall. Mean RV-GLS in the inferior wall was -23.2 ± 4.4% in the aortic (Ao) view and -20.7 ± 5.0% in the coronal (CV) view. The feasibility of mean RV-GLS was 100% in the anterior, lateral, and inferior walls in abnormally dilated RVs. CONCLUSION: The feasibility of all RV parameters assessed in the four-view iRotate model is good to excellent. Normal values for RV dimension and function of the anterior, inferior, and lateral RV walls have been established. Further studies and dedicated RV speckle-tracking software are warranted to discover the full potential of this new technique.

Limitations and difficulties of echocardiographic short-axis assessment of paravalvular leakage after corevalve transcatheter aortic valve implantation.

To make assessment of paravalvular aortic leakage (PVL) after transcatheter aortic valve implantation (TAVI) more uniform the second Valve Academic Research Consortium (VARC) recently updated the echocardiographic criteria for mild, moderate and severe PVL. In the VARC recommendation the assessment of the circumferential extent of PVL in the short-axis view is considered critical. In this paper we will discuss our observational data on the limitations and difficulties of this particular view, that may potentially result in overestimation or underestimation of PVL severity.

A granular approach to improve reproducibility of the echocardiographic assessment of paravalvular regurgitation after TAVI.

Paravalvular leak (PVL) after transcatheter aortic valve implantation (TAVI) is challenging to quantitate. Transthoracic echocardiography (TTE) is the main tool used for the assessment of PVL but is modestly reproducible. We sought to develop a reproducible echocardiographic approach to assess PVL in the post-TAVI setting. Four observers independently analyzed eleven parameters of PVL severity in 50 pre-discharge TTE studies performed after TAVI. The parameters included color-Doppler parameters [jet circumferential extent (CE) and planimetered vena contracta area in the short-axis view and jet breadth and qualitative features in the long-axis views], continuous-wave Doppler parameters [jet velocity time integral (VTI) and pressure half time (PHT)], quantitative Doppler parameters (regurgitation volume and fraction and effective regurgitant orifice area), aortic diastolic flow reversal and valve stent eccentricity. Intraclass correlation coefficient (ICC) and coefficient of variation (CV) for numerical parameters and kappa coefficient (κ) for categorical parameters were calculated for inter- and intra-observer comparisons. Inter-observer ICC was highest and CV lowest for CE (0.88 and 0.36), jet origin breadth (0.82 and 0.39), jet qualitative features in long-axis views (0.87 and 0.26), jet VTI (0.87 and 0.04) and PHT (0.73 and 0.10). Similar results were found in intra-observer comparisons. A 2-step granular approach combining the most reproducible parameters was used to grade PVL by the four observers. Inter-observer agreement was achieved in 86 % of cases (κ = 0.79). Combining color Doppler and continuous wave Doppler parameters in a granular algorithm yields excellent reproducibility of PVL assessment by TTE.

A Novel 13-Segment Standardized Model for Assessment of Right Ventricular Function Using Two-Dimensional iRotate Echocardiography.

AIMS: The aim of this study was to evaluate the feasibility of transthoracic two-dimensional (2D) iRotate, a new echo modality, to assess the whole right ventricle (RV) from a single transducer position based on anatomic landmarks. METHODS AND RESULTS: The anatomic landmarks were first defined based on three-dimensional echocardiographic datasets using multiplane reconstruction analyses. Thereafter, we included 120 healthy subjects (51% male, age range 21-67 years). Using 2D iRotate, four views of the RV could be acquired based on these landmarks. The anterior, lateral, inferior wall (divided into three segments: basal-mid-apical), and right ventricular outflow tract (RVOT) anterior wall of the RV were determined. The feasibility of visualization of RV segments and tricuspid annular plane systolic excursion (TAPSE) and tissue Doppler imaging (TDI) measurements were assessed. To evaluate this model for diseased RVs, a small pilot study of 20 patients was performed. In 98% of healthy subjects and 100% of patients, iRotate mode was feasible to assess the RV from one single transducer position. In total, 86% and 95%, respectively, of the RV segments could be visualized. The visualization of the RVOT anterior wall was worse 23% and 75%, respectively. TAPSE and TDI measurements on all four views were feasible 93% and 92%, respectively, of the healthy subjects and in 100% of the patients. CONCLUSION: With 2D iRotate, a comprehensive evaluation of the entire normal and diseased RV is feasible from a fixed transducer position based on anatomic landmarks. This is less time-consuming than the multiview approach and enhances accuracy of RV evaluation. Imaging of the RVOT segment remains challenging.

Assessment of ventricular function in adults with repaired Tetralogy of Fallot using myocardial deformation imaging.

AIMS: Many patients with repaired Tetralogy of Fallot (ToF) have right ventricular (RV) volume overload due to pulmonary regurgitation (PR). We studied the effect of volume overload on global and regional RV and left ventricular (LV) deformation, and their relationships with conventional diagnostic parameters. METHODS AND RESULTS: In this cross-sectional study, 94 prospectively recruited ToF patients (61% male, age 32.8 ± 9.5 years, age at repair 1.9 [0.8-5.7] years, 39% pulmonary homograft) and 85 healthy controls of similar age and sex underwent echocardiography and electrocardiography. In a subset of patients, cardiac magnetic resonance imaging, bicycle ergometry, and NT-proBNP measurement were performed within the same day. With speckle-tracking echocardiography, we analysed peak systolic global longitudinal strain (GLS), segmental longitudinal strain and strain rate of the RV free wall, LV lateral wall, and septum. Patients had a lower RV free wall strain than controls (-18.1 ± 4.5 vs. -26.5 ± 4.5%, P < 0.001), especially at the apical segment (-15.9 ± 7.4 vs. -28.2 ± 7.7%, P < 0.001), and lower RV strain rate. LV GLS was also lower (-17.4 ± 2.5 vs. -19.6 ± 1.9%, P < 0.001), mainly due to the interventricular septum. Patients with PR >25% had higher LV GLS and RV free wall strain than patients with PR ≤25% (P = 0.004, P = 0.039, respectively). No relationships were found with NT-proBNP or exercise capacity. CONCLUSION: RV free wall strain and strain rate are decreased in adults late after ToF repair, especially at the apical segment suggesting that apical function is most affected in these RVs. Regarding the LV, septal strain is decreased indicating that RV dysfunction adversely affects LV function, probably by mechanical coupling of the ventricles.

Assessment of subendocardial contractile function in aortic stenosis: a study using speckle tracking echocardiography.

BACKGROUND: Angina and an electrocardiographic strain pattern are potential manifestations of subendocardial ischemia in aortic stenosis (AS). Left ventricular (LV) twist is known to increase proportionally to the severity of AS, which may be a result of loss of the inhibiting effect of the subendocardial fibers due to subendocardial dysfunction. It has also been shown that the ratio of LV twist to circumferential shortening of the endocardium (twist-to-shortening ratio [TSR]) is a reliable parameter of subendocardial dysfunction. The aim of this study was to investigate whether these markers are increased in AS patients with angina and/or electrocardiographic strain. METHODS: The study comprised 60 AS patients with an aortic valve area <2.0 cm(2) and LV ejection fraction >50%, and 30 healthy-for age and gender matched-control subjects. LV rotation parameters were determined by speckle tracking echocardiography. RESULTS: Comparison of patients without angina and strain (n = 22), with either angina or strain (n = 28), and with both angina and strain (n = 8), showed highest peak systolic LV apical rotation, peak systolic LV twist, and TSR, in patients with more signs of subendocardial ischemia. In a multivariate linear regression model, only severity of AS and the presence of angina and/or strain could be identified as independent predictors of peak systolic LV twist and TSR. CONCLUSIONS: Peak systolic LV twist and TSR are increased in AS patients and related to the severity of AS and symptoms (angina) or electrocardiographic signs (strain) compatible with subendocardial ischemia.

New Scores for the Assessment of Mitral Stenosis Using Real-Time Three-Dimensional Echocardiography.

Nonsurgical management of patients with symptomatic mitral valve stenosis has been established as the therapeutic modality of choice for two decades. Catheter-based balloon dilation of the stenotic valvular area has been shown, at least, as effective as surgical interventions. Unfavorable results of catheter-based interventions are largely due to unfavorable morphology of the valve apparatus, particularly leaflets calcification and subvalvular apparatus involvement. A mitral valve score has been proposed in Boston, MA, about two decades ago, based on morphologic assessment of mitral valve apparatus by two-dimensional (2D) echocardiography to predict successful balloon dilation of the mitral valve. Several other scores have been developed in the following years in order to more successfully predict balloon dilatation outcome. However, all those scores were based on 2D echocardiography, which is limited by ability to distinguish calcification and subvalvular involvement. The introduction of new matrix-based ultrasound probe has allowed 3D echocardiography (3DE) to provide more detailed morphologic analysis of mitral valve apparatus including calcification and subvalvular involvement. Recently, a new 3DE scoring system has been proposed by our group, which represents an important leap into refinement of the use of echocardiography guiding mitral valve interventions.

Assessment of the aortic annulus by multislice computed tomography, contrast aortography, and trans-thoracic echocardiography in patients referred for transcatheter aortic valve implantation.

OBJECTIVE: We sought to determine the level of agreement and the reproducibility of trans-thoracic echocardiography (TTE), contrast aortography (CA) and multislice computed tomography (MSCT) for the assessment of the aortic annulus, in patients referred for Transcatheter Aortic Valve Implantation (TAVI). BACKGROUND: Correct measurement of the aortic annulus is important for TAVI. METHODS: The dimensions of the aortic annulus were measured using TTE, CA and MSCT in 70 patients with severe aortic stenosis, referred for TAVI. Agreement between imaging techniques and interobserver variability was assessed using the Bland - Altman method and a linear regression model. RESULTS: The MSCT Coronal view provided the largest mean annulus diameter (26.3 mm) followed by CA (24.4 mm), MSCT Mean (23.7 mm), TTE (22.6 mm), and MSCT Sagittal (21.8 mm) view. Differences in the annulus measurements were significant: MSCT Coronal view versus CA (mean, 95% confidence interval, Pearson's correlation) 2.0 mm, -1.9 to 6.0 mm, r = 0.72, CA versus MSCT Mean 0.2 mm, -3.3 to 3.7 mm, r = 0.76, MSCT Mean versus TTE 1.3 mm, -2.9 to 5.5 mm, r = 0.61, TTE versus MSCT Sagittal view 0.9 mm, -3.6 to 5.4 mm, r = 0.59, CA versus TTE 1.5 mm, -3.0 to 5.9 mm, r = 0.57. Interobserver variability was: TTE (mean, 95% confidence interval, Pearson's correlation) 0.29 mm, -4.2 to 4.8 mm, r = 0.57, CA 0.14 mm, -3.5 to 3.8 mm, r = 0.77, MSCT Mean 0.20 mm, -1.4 to 1.8 mm, r = 0.95. CONCLUSIONS: We found significant differences in the dimensions of the aortic annulus measured by MSCT, CA, and TTE. Interobserver variability for TTE and CA was substantially higher compared with MSCT.

Single-photon emission computed tomography for assessment of myocardial viability.

Left ventricular dysfunction in patients with chronic coronary artery disease may be a result of dysfunctional but viable myocardium due to myocardial hibernation. Coronary revascularisation may substantially improve regional and global left ventricular dysfunction and long-term survival if a substantial amount of dysfunctional but viable myocardium is present. Because coronary revascularisation, by percutaneous coronary intervention or coronary bypass surgery, is associated with an increased periprocedural risk in patients with severe left ventricular dysfunction, careful preprocedural selection is needed. Assessment of myocardial viability with SPECT may facilitate clinical decision making and should be considered in patients with ischaemic left ventricular dysfunction who are eligible for coronary revascularisation. The most frequently used SPECT protocols use thallium-201 (201Tl) rest-redistribution, technetium-99m (99mTc) labelled viability tracers, or 18F-fluorodeoxyglucose (FDG) for assessment of myocardial glucose metabolism. Approximately 50% of the patients with ischaemic left ventricular dysfunction have a substantial amount of dysfunctional but viable myocardium on SPECT and should be considered for coronary revascularisation. The absence of myocardial viability can help to identify patients who will not benefit from high-risk percutaneous coronary interventions or surgery.

Validation of a new score for the assessment of mitral stenosis using real-time three-dimensional echocardiography.

BACKGROUND: The aim of this study was to validate a new real-time three-dimensional echocardiography (RT3DE) score for evaluating patients with mitral stenosis (MS). METHODS: A two-staged study was conducted. In the first stage, the feasibility of a new RT3DE score was assessed in 17 patients with MS. The second stage was planned to validate the RT3DE score in 74 consecutive patients undergoing percutaneous mitral valvuloplasty. The new RT3DE score was constructed by dividing each mitral valve (MV) leaflet into 3 scallops and was composed of 31 points (indicating increasing abnormality), including 6 points for thickness, 6 for mobility, 10 for calcification, and 9 for subvalvular apparatus involvement. The total RT3DE score was calculated and defined as mild (<8), moderate (8-13), or severe (>or=14). MV morphology was assessed using Wilkins's score and compared with the new RT3DE score. RESULTS: In the first stage, the RT3DE score was feasible and easily applied to all patients, with good interobserver and intraobserver agreement. In the second stage, RT3DE improved MV morphologic assessment, particularly for the detection of calcification and commissural splitting. Both scores were correlated for assessment of thickness and calcification (r = 0.63, P < .0001, and r = 0.44, P < .0001, respectively). Predictors of optimal percutaneous mitral valvuloplasty success by Wilkins's score were leaflet calcification and subvalvular apparatus involvement, and those by RT3DE score were leaflet mobility and subvalvular apparatus involvement. The incidence and severity of mitral regurgitation were associated with high-calcification RT3DE score. CONCLUSION: The new RT3DE score is feasible and highly reproducible for the assessment of MV morphology in patients with MS. It can provide incremental prognostic information in addition to Wilkins's score.

Assessment of mitral annular velocities by speckle tracking echocardiography versus tissue Doppler imaging: validation, feasibility, and reproducibility.

BACKGROUND: Mitral annular velocity may be measured angle independently by speckle tracking echocardiography (STE), in contrast with tissue Doppler imaging (TDI). The purpose of the current study was to compare STE and TDI, with respect to 1) the accuracy of velocity measurements in a moving phantom, 2) the feasibility and reproducibility of measurement of mitral annular velocities in a clinical setting, and 3) the estimation of left ventricular filling pressures using mitral annular velocities. METHODS: The velocity of a moving phantom, using different angles of insonation, and mitral annular velocities of 80 nonselected patients and 50 healthy volunteers were determined using TDI and STE. A subgroup of 20 patients was studied during right-sided heart catheterization. RESULTS: When the motion direction of the phantom was parallel to the ultrasound beam, both TDI and STE determined velocities accurately. With increasing angle of insonation, TDI-derived velocity decreased, whereas STE-derived velocity remained unchanged. The feasibility of mitral annular velocities measured by TDI and STE was comparable (98% vs 95%, P = not significant). Although for both techniques correlations between measured mitral annular velocities at repeated examinations were good, the test-retest variability of mitral annular velocities by TDI was higher. E/Em ratio by STE correlated better to pulmonary capillary wedge pressure (R(2) = 0.51, P < .001) compared with E/Em ratio derived from TDI (R(2) = 0.35, P < .01), although the difference in correlation was not statistically significant because of the limited sample size. CONCLUSION: Tissue velocities can be accurately determined by STE in a moving phantom and are angle independent, in contrast with TDI measurements. Furthermore, STE is a feasible and better reproducible method for the assessment of mitral annular velocities in a clinical setting.

Importance of transducer position in the assessment of apical rotation by speckle tracking echocardiography.

BACKGROUND: Speckle tracking echocardiography is increasingly used to quantify left ventricular (LV) twist. However, one of the limitations of the assessment of LV twist by speckle tracking echocardiography is the crucial dependence on correct acquisition of a LV apical short-axis. This study sought to assess the influence of transducer position on LV apical rotation measurements. METHODS: The study population consisted of 58 consecutive healthy volunteers (mean age 38 +/- 13 years, 25 men). To obtain parasternal short-axis images at the LV apical level, the following protocol was used. From the standard parasternal position (LV and aorta most inline, with the mitral valve tips in the middle of the sector) an as-circular-as-possible short-axis image of the LV apex, just proximal to the level with end-systolic LV luminal obliteration, was obtained by angulation of the transducer (position 1). From this position, the position of the transducer was changed to one (position 2) and two (position 3) intercostal spaces more caudal with subsequent similar transducer adaptations. RESULTS: In 8 volunteers (14%) parasternal image quality was insufficient for speckle tracking echocardiography. In 13 volunteers (22%) the LV apical short-axis could only be obtained from one transducer position. In the remaining volunteers with two (n = 27) or three (n = 10) available transducer positions, a more caudal transducer position was associated with increased measured LV apical rotation. Mean measured LV apical rotation was 5.2 +/- 1.8 degrees at position 1, 7.3 +/- 2.6 degrees at position 2 (P < .001), and 8.7 +/- 2.2 degrees at position 3 (P < .001 vs position 1 and P < .05 vs position 2). CONCLUSION: A more caudal transducer position is associated with increased measured LV apical rotation.

Assessment of left ventricular ejection fraction after myocardial infarction using contrast echocardiography.

AIMS: Despite its relatively high intra- and inter-observer variability for left ventricular ejection fraction (LV-EF) echocardiography is clinically still the most used modality to assess LV-EF. We studied whether adding a second-generation microbubble contrast agent could decrease this variability. METHODS AND RESULTS: Forty-eight patients underwent transthoracic echocardiography in second-harmonic mode (SHI) with and without contrast within 5 days after an acute myocardial infarction. LV-EF was determined using the Simpson's biplane method. With contrast intra-observer variability decreased from 12.5 +/- 11.5% to 7.0 +/- 7.0% (P < 0.001) and inter-observer variability decreased from 16.9 +/- 9.9% to 7.0 +/- 6.2% (P < 0.001). Bland-Altman analysis confirmed these findings by demonstrating smaller 95% limits of agreement for both the intra- and inter-observer variability when contrast was used. This improvement in intra- and inter-observer variability was seen to a comparable extent in patients with moderate-to-poor and good quality SHI echocardiograms. CONCLUSION: Echo contrast significantly improves intra- and inter-observer variability for LV-EF, both in patients with moderate-to-poor and good quality SHI echocardiograms.

Assessment of left atrial volume and function by real-time three-dimensional echocardiography.

BACKGROUND: Determination of left atrial (LA) size and function is important in clinical decision-making. Calculation of LA volume (LAV) is the most accurate index of LA size. AIM: To compare real-time 3-dimensional echocardiography (RT3DE) and 2-dimensional echocardiography (2DE) for calculation of LAV and function. METHODS: Fifty patients were studied using 2DE and RT3DE for calculating LAV including: Maximum (V max), minimum (V min) and pre-atrial contraction (V pre A) volumes. For 2DE, the formula: LAV=8(A1) (A2)/3pi (L) was used, while for RT3DE, offline analysis was performed using commercially available software. LA function indices including Total Atrial Stroke Volume (TASV), active ASV (AASV), Total Atrial Emptying Fraction (TAEF), active AEF (AAEF), passive AEF (PAEF), and Atrial Expansion Index (AEI) were calculated. RESULTS: Patients were classified into 2 equal groups: group I with normal V max (< 50 ml) and group II with V max (> or = 50 ml). Good correlation was obtained between RT3DE and 2DE for LAV (r=0.64, p=0.001) in group I and (r=0.83, p<0.0001) in group II. In group I, LAV and functions showed no significant difference by both techniques, while in group II, the V min and V pre A were significantly lower by RT3DE than 2DE (p=0.009, 0.006). TAEF, AEI, and PAEF indices were significantly higher by RT3DE than 2DE in group II. CONCLUSION: RT3DE provides a reproducible assessment of active and passive LA function by volumetric cyclic changes. It is comparable and may be superior to 2DE due to its higher sensitivity to volume changes.

Assessment of left atrial ejection force in hypertrophic cardiomyopathy using real-time three-dimensional echocardiography.

The study included 30 patients with hypertrophic cardiomyopathy (HCM) (obstructive and nonobstructive) and 15 control subjects. End-diastolic mitral annulus area (MAA(3D)) and mitral valve area (MVA(3D)) were measured by real-time 3-dimensional (3D) echocardiography. MVA(2D) and peak mitral inflow A wave velocity (V) were measured by 2-dimensional (2D) echocardiography. Left atrial ejection force (LA-EF) was calculated by 2D echocardiography and real-time 3D echocardiography using the formula: 0.5 x 1.06 x (MAA or MVA) x V2, where (1.06) is blood viscosity. LA-EF(2D-MVA), LA-EF(3D-MVA), LA-EF(3D-MAA), and V were significantly higher in patients with HCM than control subjects (P < .001). LA-EF(2D-MVA) and LA-EF(3D-MVA) were lower than LA-EF(3D-MAA) in HCM only (P < .001). In obstructive HCM, LA-EF(2D-MVA), LA-EF(3D-MVA), LA-EF(3D-MAA), and V were significantly higher than in nonobstructive HCM (P < .05). Left ventricular outflow tract gradient contributed independently to high LA-EF in obstructive HCM. We concluded that HCM is associated with higher LA-EF than normal, and higher in obstructive HCM than nonobstructive indicating a higher atrial workload that is reflected by LA-EF(3D-MAA).