Usefulness of real-time three-dimensional echocardiography for reliable measurement of cardiac output in patients with ischemic or idiopathic dilated cardiomyopathy

Echocardiography in Advanced Heart Failure for Diagnosis, Management, and Prognosis

Advanced heart failure, an end-stage disease characterized by high mortality and morbidity despite standard medical therapy, requires various therapeutic strategies like heart transplant and long-term mechanical circulatory support. Echocardiography is the main imaging technique to identify transitions to advanced stages of disease and guide risk stratification and therapeutic decision-making processes. Progressive development of advanced echocardiographic techniques allows more comprehensive assessment of the hemodynamic and structural profiles of patients with advanced heart failure, and its use in clinical practice continues to expand. This article provides an overview of basic and emerging echocardiographic tools to assess patients with advanced heart failure.

From left ventricular ejection fraction to cardiac hemodynamics: role of echocardiography in evaluating patients with heart failure

In clinical practice heart failure (HF) patients are generally classified on the basis of left ventricular (LV) ejection fraction. This approach, however, has important limitations. According to the definition of HF as a clinical syndrome that results from any impairment of LV filling or ejection of blood, a more articulated hemodynamic categorization of HF patients taking into account both LV forward flow and filling pressure would be desirable. However, the reliability of hemodynamic measures using echocardiographic techniques, which are the most used in current clinical practice for evaluation of HF patients, needs to be clarified. The aim of this article, therefore, is to verify whether echocardiography has acceptable feasibility, accuracy and reproducibility for the noninvasive evaluation of LV hemodynamics. This evaluation is necessary to progress to a hemodynamic characterization of HF patients that would ultimately overcome the HF classification based on ejection fraction.

Predicting fluid responsiveness with transthoracic echocardiography is not yet evidence based

An essential part of intensive care is to accurately identify fluid responders among patients with circulatory failure. Over the past few years, new techniques have been assessed for rapid and non-invasive prediction of fluid responsiveness. As transthoracic echocardiography (TTE) is becoming an integrated tool in the intensive care unit, this systematic review examined studies evaluating the predictive value of TTE for fluid responsiveness. In October 2012, we searched Pubmed, EMBASE and Web of Science for studies evaluating the predictive value of TTE-derived variables for fluid responsiveness defined as change in thermodilution cardiac output or stroke volume after a fluid challenge or a passive leg raising test. The use of thermodilution was used as inclusion criterion because it is the only method validated to show the change in cardiac output or stroke volume, which defines fluid responsiveness. Of the 4294 evaluated citations, only one study fully met our inclusion criteria. In this study, the predictive value of variations in inferior vena cava diameter (> 16%) for fluid responsiveness was moderate with sensitivity of 71% [95% confidence interval (CI) 44-90], specificity of 100% (95% CI 73-100) and an area under the receiver operating curve of 0.90 (95% CI 0.73-0.98). Only one study of TTE-based methods fulfilled the criteria for valid assessment of fluid responsiveness. Before recommending the use of TTE in predicting fluid responsiveness, proper evaluation including thermodilution technique as the gold standard is needed.

Real time triplane echocardiography in the assessment of the functional area of prosthetic aortic valves: reliability and feasibility

PURPOSE

Our study is aimed at evaluating the feasibility and reliability of a simple method for the measurement of the functional area of prosthetic aortic valves (EOA). Three-dimensional echocardiography has proven accurate for left ventricular volume, stroke volume, and aortic valve area measurement. We studied the feasibility and reliability of real time simultaneous triplane echocardiography (RT3P) for assessing the EOA with a fast formula based on the principle of continuity equation, in which we replaced Doppler-derived stroke volume (SV) with SV directly measured with RT3P.

METHODS AND RESULTS

EOA of prosthetic aortic valves were measured in 23 consecutive patients requiring periodical follow up. EOA was calculated using Doppler continuity equation (DCE) and the RT3P method by replacing Doppler-derived SV with SV measured with real time triplane echocardiography. We compared functional areas obtained with the two methods with the prosthetic area indicated in the manufacturer's specifications and with the mean transprosthetic gradient. Both methods had a good correlation with the area indicated by the manufacturer. RT3P revealed an inverse correlation between functional area and mean gradient that was better than DCE (P = 0.0359). Inter- and intraobserver variability was not different between the two methods. Execution time was significantly shorter for RT3P.

CONCLUSIONS

RT3P is a simple method that can be performed quite rapidly, and can complement the overall assessment of prosthetic valve function. Further studies can confirm our technique.

Accuracy of three-dimensional echocardiography in patients with prior anteroseptal myocardial infarction

BACKGROUND

Echocardiography is the most feasible modality for monitoring cardiac volume and function. However, conventional two-dimensional echocardiography (2DE) is frequently not accurate in measuring cardiac performance in cases of abnormal left ventricular wall motion, because of the geometric assumptions. Quantitative gated scintigraphy and magnetic resonance imaging are reliable modalities, but are expensive and not feasible for repetitive use. Real-time three-dimensional echocardiography (RT3DE) has been proved to be applicable in daily practice. The purpose of this study was to confirm the superiority of RT3DE to 2DE in assessing cardiac volume and function in patients with abnormal wall motion.

METHODS

The subjects were 41 patients with old anteroseptal myocardial infarction who underwent left ventricular volume and functional measurement by RT3DE, 2DE, and left ventriculography (LVG). End-diastolic volume (EDV), end-systolic volume (ESV), and ejection fraction (EF) from RT3DE and 2DE were measured and compared with results from LVG.

RESULTS

RT3DE correlated well with LVG in measurements of EDV, ESV, and EF (r = 0.815, 0.940, and 0.812, respectively; P < 0.001 each). Likewise, 2DE correlated with LVG, but underestimated left ventricular volume, particularly EDV (r = 0.652, 0.909, and 0.761, respectively; P < 0.001 each).

CONCLUSION

Values derived from RT3DE were closer to those from LVG than were values derived from 2DE. RT3DE provides important information on cardiac function in patients with prior anteroseptal myocardial infarction.

Real-time three-dimensional echocardiography in aortic stenosis: a novel, simple, and reliable method to improve accuracy in area calculation

AIMS

The aim of the study was to validate a novel formula for aortic area, based on the principle of continuity equation (CE), that substitutes Doppler-derived stroke volume (SV) by SV directly measured with real-time three-dimensional (RT3D) echo and semi-automated border detection. RT3D has proved outstanding accuracy for left ventricular volume calculation. So far, however, neither this potential has been applied to haemodynamic assessment, nor RT3D has succeeded in the evaluation of aortic valve disease.

METHODS AND RESULTS

Aortic area was measured in 41 patients with aortic stenosis using Gorlin's equation, Hakki's formula, Doppler CE, two-dimensional Simpson's volumetric method, and by the novel RT3D method. RT3D has the best linear association and absolute agreement with Gorlin of all non-invasive methods r = 0.902, intraclass correlation coefficient (ICC) = 0.846, better than CE (r = 0.646, ICC = 0.626) and two-dimensional volumetric method (r = 0.627, ICC = 0.378). Linear and Passing-Bablok regression show that RT3D fits better to Gorlin (r(2) = 0.814) than CE (r(2) = 0.417) and two-dimensional method (r(2) = 0.393). Its accuracy is comparable to Hakki's formula, routinely employed in catheter laboratories. Inter- and intraobserver agreements (ICC) were, respectively, 0.732 and 0.985, better than CE (0.662, 0.857). RT3D also grades most efficiently the severity of aortic stenosis as mild, moderate, or severe (weighted kappa = 0.932). RT3D underestimates aortic area (95% CI 0.084-0.193). ROC curves, however, show that the optimal cutoff point to consider aortic stenosis severity remains close to 1 cm(2) (1.06 cm(2)).

CONCLUSIONS

RT3D is more accurate than CE and than two-dimensional volumetric methods to calculate area and to grade the severity of aortic stenosis. Area obtained by three-dimensional echo is slightly underestimated, but its range is clinically negligible.

Real‐time three‐dimensional echocardiography provides novel and useful anatomic insights of perimembranous ventricular septal aneurysm

BACKGROUND

Real-time three-dimensional echocardiography (RT3DE) is a new image modality, and it can display a unique image reconstruction in a variety of heart diseases. However, clinical assessment of ventricular septal aneurysm (VSA) by RT3DE has not been reported. This pilot prospective study is to survey what kinds of new insights of VSA can be provided by RT3DE as compared with conventional 2-dimensional echocardiography (2DE).

METHODS

We investigated the diagnostic value of RT3DE and 2DE in 60 consecutive patients with VSA. From different transthoracic windows, structures of interest can be displayed from any orientation through adjusting cropping and slicing the RT3DE datasets. The results were compared with those in 2DE.

RESULTS

RT3DE reconstruction of VSA was feasible in 56 of 60 patients (93%). When compared with 2DE, additional information provided by RT3DE included blood flow through left ventricle to right ventricle, visualization of VSD enface border in 56 patients (93%), morphology of the VSA from apical short axis view in 48 patients (86%), hypertrophied margin of the interventricular septum in 26 patients (43%), dynamic changes of VSA and tricuspid valve in 18 patients (30%), adhesion of chordae tendineae in VSA in 16 patients (26%).

CONCLUSIONS

Structures of interest can be evaluated from unique RT3DE in any orientation during scanning. RT3DE offers additional novel views and has the advantages of not only displaying better visualization of VSA, but also adequately showing the spatial relationship with its adjacent structures. It can provide novel and useful anatomic insights than 2DE while assessing patients with VSA.

Three-Dimensional Echocardiographic Evaluation of the Heart Chambers: Size, Function, and Mass

The major advantage of three-dimensional (3D) ultrasound imaging of the heart is the improvement in the accuracy of the echocardiographic evaluation of cardiac chamber volumes, which is achieved by eliminating the need for geometric modeling and the errors caused by foreshortened 2D views. In this article, we review the literature that has provided the scientific basis for the clinical use of 3D ultrasound imaging of the heart in the assessment of cardiac chamber size, function, and mass, and discuss its potential future applications.

Actualización en técnicas de imagen cardiaca. Ecocardiografía, resonancia magnética en cardiología y tomografía computarizada con multidetectores

This article contains a review of the most significant publications on non-invasive recent cardiac imaging techniques in 2005. The increasing importance of technological innovation in echocardiography is reflected in the sections on three dimensional echocardiography, contrast echocardiography, and myocardial deformation measurement techniques (i.e., strain echocardiography). The most important developments affecting cardiology in the techniques of magnetic resonance imaging and multidetector computed tomography are also summarized. This review ends with a detailed description of the contributions made by imaging techniques to the diagnosis of aortic disease.

Quantitative Real-time 3-Dimensional Stress Echocardiography: A Preliminary Investigation of Feasibility and Effectiveness

BACKGROUND

Use of rapidly emerging real-time 3-dimensional (3D) echocardiography promises to improve the diagnostic accuracy of stress echocardiography (SE). However, widespread acceptance of 3D-SE, based on real-time 3D echocardiography, is hampered in part by lack of efficient, accurate, and objective analysis tools.

METHODS

We propose novel algorithms for interactive visualization, registration (alignment), and quantitative analysis of prestress and poststress real-time 3D echocardiography to facilitate an objective diagnosis. In a preliminary evaluation, two experts independently performed wall-motion analysis in 15 patients with known/suspected coronary artery disease, using the novel quantitative 3D-SE methods.

RESULTS

Compared with previously reported values for conventional 2-dimensional SE, improved interexpert agreement (kappa = 0.85) was observed for segment-wise classification of normal/abnormal wall motion using the novel 3D-SE methods. Overall, 6 of 6 patients with abnormal myocardial segments were correctly identified by both experts with 3D-SE, compared with 4 of 6 with conventional 2-dimensional SE.

CONCLUSION

Initial results are promising and indicate the feasibility and potential of our proposed quantitative 3D-SE methodologies for improving diagnosis of wall-motion abnormalities.

Three-Dimensional Echocardiography

Over the past 3 decades, echocardiography has become a major diagnostic tool in the arsenal of clinical cardiology for real-time imaging of cardiac dynamics. More and more, cardiologists' decisions are based on images created from ultrasound wave reflections. From the time ultrasound imaging technology provided the first insight into the human heart, our diagnostic capabilities have increased exponentially as a result of our growing knowledge and developing technology. One of the most significant developments of the last decades was the introduction of 3-dimensional (3D) imaging and its evolution from slow and labor-intense off-line reconstruction to real-time volumetric imaging. While continuing its meteoric rise instigated by constant technological refinements and continuing increase in computing power, this tool is guaranteed to be integrated in routine clinical practice. The major proven advantage of this technique is the improvement in the accuracy of the echocardiographic evaluation of cardiac chamber volumes, which is achieved by eliminating the need for geometric modeling and the errors caused by foreshortened views. Another benefit of 3D imaging is the realistic and unique comprehensive views of cardiac valves and congenital abnormalities. In addition, 3D imaging is extremely useful in the intraoperative and postoperative settings because it allows immediate feedback on the effectiveness of surgical interventions. In this article, we review the published reports that have provided the scientific basis for the clinical use of 3D ultrasound imaging of the heart and discuss its potential future applications.

Left ventricular remodelling index (LVRI) in various pathophysiological conditions: a real-time three-dimensional echocardiographic study

BACKGROUND

Various studies have reported a close correlation between real-time three-dimensional echocardiography (RT3DE) and cine magnetic resonance imaging studies for the assessment of cardiac volumes and mass.

OBJECTIVE

The aim of our study was to evaluate changes in left ventricular volumes and mass in subjects with different pathophysiological conditions. A ratio between left ventricular mass and end-diastolic volume (LVRI), detected by RT3DE, was used to describe various patterns of left ventricular remodelling.

METHODS

RT3DE was performed to calculate left ventricular end-diastolic (LVEDV) and end-systolic volume (LVESV), ejection fraction (LVEF) and mass in 220 selected subjects. Of these, 152 were healthy volunteers, 19 top-level rowers, 23 patients with dilated cardiomyopathy and 26 patients with hypertrophic cardiomyopathy. Off-line analysis was performed by two independent operators by tracing manual endocardial and epicardial borders of the left ventricle through eight cutting planes. Inter- and intra-observer variability were calculated.

RESULTS

Despite the increase in LV volume and mass in the rowers, LVRI remained unchanged compared with control subjects (p = 0.455), while significantly lower values were found patients with dilated cardiomyopathy (p<0.001) and significantly higher values in patients with hypertrophic cardiomyopathy (p<0.001). There was inter- and intra-observer variability.

CONCLUSION

The LVRI may serve as a simple and useful indicator of left ventricular adaptation to physiological and pathological conditions.

Comparison of Contrast-enhanced Real-time Live 3-Dimensional Dobutamine Stress Echocardiography with Contrast 2-Dimensional Echocardiography for Detecting Stress-induced Wall-motion Abnormalities

BACKGROUND

Two-dimensional (2D) contrast-enhanced dobutamine stress echocardiography (DSE) is used clinically to diagnose stress-induced wall-motion abnormality (WMA). We hypothesized that contrast-enhanced real-time 3-dimensional (3D) DSE could improve the detection rate of WMA, because from a single full-volume acquisition, multiple segments can be visualized.

METHODS

We acquired both 2D and 3D DSE in 78 patients with known or suggested coronary artery disease (mean age: 65 years; 44 men). Dobutamine was infused using a standard protocol, and atropine added, if required. For 2D DSE, the intravenous contrast agent was injected at each stage and images displayed in a quadscreen format. For 3D DSE, contrast harmonic 3D data sets (full volumes) were acquired at baseline and peak stress. Using custom software, 3 short-axis views (from apex to base) were created, and wall motion scored using a wall-motion score index using a 16-segment model. A positive stress test was defined as new or worsened WMA or fixed abnormality during stress.

RESULTS

Heart rate increased from 72 +/- 13 to 133 +/- 15/min (86 +/- 11% of age-predicted). A total of 1248 segments were analyzed at each stage for both modalities. A single segment at baseline and 5 segments at peak stress could not be assessed with contrast 2D DSE. In contrast, 88 segments at baseline and 39 segments at peak stress could not be assessed with contrast 3D DSE. With 3D DSE, the majority of uninterpretable segments were in the anterior and lateral walls. Significant correlations were noted between wall-motion score index by 2D and 3D DSE at baseline (r = 0.78) and peak stress (r = 0.83). The concordance rate (positive/negative findings) between modalities was 69% (54/78) on a patient basis and 88% (206/234) on a perfusion territory basis. When using 2D DSE results as the gold standard, sensitivity and specificity for detecting WMA by 3D DSE was 58% and 75%, respectively. Sensitivity and specificity values were 67% and 94% for the right coronary artery, 53% and 81% for the left anterior descending coronary artery, and 88% and 100% for the left circumflex coronary artery territory, respectively.

CONCLUSION

Contrast-enhanced 3D DSE was feasible in the majority of patients. However, the moderate concordance between both modalities was a result of: (1) difficulties in visualizing the anterolateral segments because of the relatively large imprint of the transducer; and (2) lower frame rates with 3D DSE resulting in the erroneous diagnosis of dyssynchrony.

Real-Time 3-Dimensional Echocardiography: A Review of the Development of the Technology and Its Clinical Application

Real-time 3-dimensional echocardiography (RT3DE) is a new imaging technique that can provide accurate, important, and additional information concerning cardiovascular morphology, pathology, and function. This article will review the development of the technology of RT3DE and its clinical application. As the technique continues to evolve, RT3DE is bound to play an increasingly important role in the diagnosis, prognosis, and treatment of patients with various forms of cardiovascular disease.