CRT
: Cardiac resynchronization therapy
ECG
: Electrocardiographic
LV
: Left ventricular
RV
: Right ventricular
SDI
: Systolic dyssynchrony index
TEE
: Transesophageal echocardiographic
3D
: Three-dimensional
3DE
: Three-dimensional echocardiographic
TTE
: Transthoracic echocardiographic
TV
: Tricuspid valve
2D
: Two-dimensional

Three-dimensional (3D) echocardiographic (3DE) imaging represents a major innovation in cardiovascular ultrasound. Advancements in computer and transducer technologies permit real-time 3DE acquisition and presentation of cardiac structures from any spatial point of view. The usefulness of 3D echocardiography has been demonstrated in (1) the evaluation of cardiac chamber volumes and mass, which avoids geometric assumptions; (2) the assessment of regional left ventricular (LV) wall motion and quantification of systolic dyssynchrony; (3) presentation of realistic views of heart valves; (4) volumetric evaluation of regurgitant lesions and shunts with 3DE color Doppler imaging; and (5) 3DE stress imaging. However, for 3D echocardiography to be implemented in routine clinical practice, a full understanding of its technical principles and a systematic approach to image acquisition and analysis are required. The main goal of this document is to provide a practical guide on how to acquire, analyze, and display the various cardiac structures using 3D echocardiography, as well as limitations of the technique. In addition, this document describes the current and potential clinical applications of 3D echocardiography along with their strengths and weaknesses.

### a. Fully Sampled Matrix-Array Transducers

An important milestone in the history of real-time 3D echocardiography was reached shortly after the year 2000, with the development of fully sampled matrix-array transducers. These transducers provided excellent real-time imaging of the beating heart in three dimensions and required significant technological developments in both hardware and software, including transducer design, microelectronic techniques, and computing.

Currently, 3DE matrix-array transducers are composed of nearly 3,000 piezoelectric elements with operating frequencies ranging from 2 to 4 MHz and from 5 to 7 MHz for transthoracic echocardiographic (TTE) and transesophageal echocardiographic (TEE) imaging, respectively. These piezoelectric elements are arranged in a matrix configuration within the transducer and require a large number of digital channels for these fully sampled elements to be connected. To reduce both …

https://www.zora.uzh.ch/id/eprint/75298/1/EurHeartCardImaging_201201.pdf

EAE/ASE Recommendations for Image Acquisition and Display Using Three-Dimensional Echocardiography

One of the most significant developments of the last decade in ultrasound imaging of the heart was the evolution of 3-dimensional (3D) imaging from slow and labor-intense offline reconstruction to real-time volumetric imaging. This imaging modality provides valuable clinical information that empowers echocardiographers with new levels of confidence in the diagnosis of heart disease. We have previously described the technological milestones in the development of real-time 3D echocardiographic (RT3DE) imaging and its major advantages over conventional 2-dimensional echocardiography (2DE) and reviewed the published literature that supported the use of this new methodology in clinical practice.1 Since 2006, the growing availability of RT3DE technology, its ease of use, and its multiple attractive features have sparked significant interest in the research community, resulting in a large number of publications, most of which have endorsed RT3DE imaging for clinical use by demonstrating its unique capabilities in different scenarios. In parallel, the clinical acceptance of this new tool has broadened significantly. The most recent clinically significant addition is matrix-array transesophageal echocardiography (TEE), which provides images of unprecedented quality that aid surgeons and interventional cardiologists in planning and guiding procedures and evaluating their outcomes.

The purpose of the present article is to review the most recent RT3DE literature and provide readers with an update on the latest developments and the current status of this noninvasive imaging tool. Because different potential applications of RT3DE imaging have been explored to various extents, they are described here separately, and each is discussed with an emphasis on the scientifically established facts, along with the known stumbling blocks and difficulties.

A firmly established advantage of 3D imaging over cross-sectional slices of the heart is the improvement in the accuracy of the evaluation of left ventricular (LV) volumes and ejection fraction (EF) by eliminating the need for geometric modeling, which …

Real-time 3-dimensional echocardiography: an integral component of the routine echocardiographic examination in adult patients?

The European Association of Echocardiography (EAE) has developed the present recommendations to assist clinical researchers in the design, implementation, and conduction of echocardiographic protocols for clinical trials and to guarantee their quality. Clinical trials should be designed and conducted based on the knowledge of the pathophysiology of the clinical condition studied, the technical characteristics of the echo-Doppler modalities, and the variability of the tested parameters. These procedures are important to choose the most reliable and reproducible techniques and parameters. Quality assurance must be guaranteed by adequate training of peripheral site operators to obtain optimal echo-Doppler data and by using a core laboratory for accurate and reproducible data analysis.

/pdf/recommendations-of-the-european-association-of-1888lpdocx.pdf

Recommendations of the European Association of Echocardiography: how to use echo-Doppler in clinical trials: different modalities for different purposes.

Echocardiography is a key assessment tool for the evaluation of cardiac structure and function. The ability to image cardiac structures using 3-dimensional (3D) echocardiography is evolving. In this article, we present some of the key features of the emerging 3D technology and review its applications with an emphasis on real-time 3D transesophageal echocardiography.

Three-Dimensional Transesophageal Echocardiography Is a Major Advance for Intraoperative Clinical Management of Patients Undergoing Cardiac Surgery: A Core Review

Valvular heart disease. The value of 3-dimensional echocardiography

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 cm2 (1.06 cm2).

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 in aortic stenosis: a novel, simple, and reliable method to improve accuracy in area calculation

http://www.journalofcardiologycases.com/article/S1878540922000202/pdf

Elsa Prieto-Moriche

Papers

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

Cardiac involvement in Adult Multisystemic Inflammatory Syndrome related to COVID-19. Two case reports