Quality Assurance and Improvement Project in Echocardiography Laboratory: The Pivotal Importance of Organizational and Managerial Processes.

Echocardiography plays a vital role in the diagnosis and management of cardiovascular conditions. Echocardiography use is progressively increasing nowadays, and this is correlated to the evolving echo indications, to the relatively new available echocardiography modes (tissue Doppler imaging, speckle tracking imaging, three-dimensional mode, etc.) and modalities (transthoracic, transesophageal, and intracardiac) along with the various available clinical approaches (point of care echo, portable echo, etc.). Quality assurance in echocardiography is correlated to appropriate use criteria, adequate equipment, standardization of performance and reporting, along with timely storage and archiving. Quality improvement plan must target strategic planning, with metrics and timeline for assessment and re-assessment of results. Improvement project aims to ensure and enhance conformity with appropriate use criteria and standardization, timely completion of exams and reports, detection of discrepancies, and continuous improvement of knowledge and skills. Strategic planning is essential in this context in order to develop organizational and managerial processes, with regular auditing for a highly professional and advanced level of echocardiography, while ensuring teamwork and standards of ethical values. Copyright:

INTRODUCTION

Echocardiography plays a vital role in the diagnosis of cardiovascular diseases. It is useful to determine the severity and progression of diseases, and it helps in the choice of optimal clinical and managerial decision. Echocardiography practice is progressively increasing nowadays, and this is related to the evolving indications (study of myocardial viability, cardiac synchrony, chemotherapy related cardiotoxicity, etc.), to the relatively new available modes (tissue Doppler imaging, speckle tracking imaging, three-dimensional mode [3D echo], etc.), to the various modalities (transthoracic, transesophageal, intracardiac) and approaches (point of care echo, portable echo, etc.).[1]

In this regard, we suggest that echocardiography must be achievable within a consistent framework of clinical standards, in order to ensure appropriate use criteria, to preserve resources, and to produce high-quality echocardiograms which are reliable and reproducible for better clinical outcome.[2345]

In this document, we sought to review and discuss standards of echocardiography in clinical practice, quality assurance (QA) and quality improvement (QI) project with an insight into the managerial and organizational facets in order to develop and implement quality evolutionary processes.

METHODS

Source data were obtained from a MEDLINE/PubMed search of the medical literature, including the PubMed “related articles” search methodology: we used the terms “echocardiography; quality,” “echocardiography; proficiency,” “echocardiography; quality improvement; practice” and “echocardiography; management.” Moreover, these terms were specifically searched in titles, abstracts, keywords, and conclusions and subsequently were used as additional bibliographic selection criteria. The search started from 2000, selected articles mainly address the quality and clinical outcome along with the managerial aspect of echocardiography rather than its pure technical feature; 60 articles found to be relevant were selected.

QUALITY ASSURANCE

Echocardiography is useful for the diagnosis and management of various cardiovascular conditions, and high-quality echocardiograms are necessary to ensure better clinical outcomes. QA implies to conform to appropriate use criteria, to use appropriate equipment, and to standardize performance, reporting, storage, and archiving.[67]

a. Appropriate use criteria:

With the extensive use of cardiac ultrasound, several exams may be performed without reasonable indication, and therefore conforming to appropriate use criteria is required to ensure quality.[34] In this regard, it is recommended to have an official echocardiography request that explicitly states the reasons for the exam in order to guide the sonographer and to keep traceability for potential auditing in this regard.[7]

From a clinical perspective, appropriate use criteria enable a better adjustment of echocardiographic indications, avoiding potential misuse or abuse, and this is a crucial step to improve clinical outcomes while preserving resources and unnecessary health expenses in a relatively restricted health-care budget.[8910]

b. Equipment:

In order to produce high-quality echocardiograms, an up-to-date equipment is required. Besides the baseline available modes (two-dimensional [2D] mode, M-mode, spectral pulsed and continuous wave Doppler, and color Doppler), contemporary machines are meant to be equipped with automatic image enhancement software, deformation imaging (DFI) software, three-dimensional (3D) software and probes, stress echo software, along with transesophageal software and probe (with 3D capability). Additionally, the echo machine should be equipped with digital storage, and an ergonomic design, with variable height and rotation of the display screen and control panel.[11] Besides the formal machines, intracardiac echo and portable machines are useful in special settings to allow for covering all or most of clinical situations, such as point of care echo or assistance for interventional procedures.[1213]

c. Standardization:

Data acquisition and image quality are of utmost importance to yield high-quality echogram with high diagnostic accuracy; sonographer should multiply views and windows in order to get better visibility, and high-quality images are essential to extract all the available sonographic information.[6]

Standardization is a crucial issue in order to ensure quality in echocardiography laboratory, and this implies conformity with guidelines (acquisition and quality of images, windows used, methods used, measurements scales, qualitative descriptors, etc.).[7] Sonographers must be adequately trained in image acquisition, adjusting all machine settings (gain, resolution, frame rate, depth, probe orientation, etc.) in order to acquire high-quality images and loops for optimal measurements and interpretation.

Measurement results should be interpreted according to standards as of latest guidelines.[14] Reference ranges of parameters for the assessment of cardiac chambers size, systolic and diastolic function, Doppler data, left ventricle (LV) 2D strain data, left atrial function, LV 3D echocardiographic data, and proximal aorta dimensions are reported as substudies of the NORRE study.[15161718192021]

Similarly, other studies reported echocardiographic recommendations for native valvular regurgitation assessment, stress echocardiography, transesophageal echocardiography, 2D speckle tracking echocardiography data (for the right atrium, right ventricle, and left atrium), and cardiac chamber quantification [Table 1].[222324252627]

Table 1

Studies reporting standardization values and reference ranges for echocardiography

Recent studies addressing standardization	Issue addressed	Journal/study or association
Evangelista et al., 2008[7]	Recommendations for standardization of performance, digital storage, and reporting of echocardiographic studies	EACVI- Eur J Echocardiogr
Flachskampf et al., 2010[24]	Recommendations for transesophageal echocardiography: Update 2010	Eur J Echocardiogr
Lancellotti et al., 2013[22]	Recommendations for assessment of native valvular regurgitation	EACVI
Kou et al., 2014[15]	Reference ranges for normal cardiac chamber size	NORRE sub-study
Caballero et al., 2015[17]	Echocardiographic reference ranges for normal cardiac Doppler data	NORRE sub-study
Wheeler et al., 2015[25]	Minimum dataset for a standard transesophageal echocardiogram: A guideline protocol	British Society of Echocardiography
Lang et al., 2015[27]	Recommendations for cardiac chamber quantification by echocardiography in adults	EACVI/ASE Eur Heart J Cardiovasc Imaging
Sugimoto et al., 2017[18]	Reference ranges for normal left ventricular 2D strain	NORRE sub-study/EACVI
Bernard et al., 2017[20]	3D echocardiographic reference ranges for normal left ventricular volumes and strain	NORRE sub-study/EACVI
Saura et al., 2017[21]	Normal reference ranges for proximal aorta dimensions	NORRE sub-study/EACVI
Sugimoto et al., 2018[19]	Reference ranges for normal left atrial function parameters	NORRE sub-study/EACVI
Badano et al., 2018[26]	Standardization of left atrial, right ventricular, and right atrial deformation imaging using two-dimensional speckle tracking echocardiography	EACVI/ASE Eur Heart J Cardiovasc Imaging
Manganaro et al., 2019[16]	Myocardial work indices and main parameters of systolic and diastolic function	NORRE sub-study/EACVI
Pellikka et al., 2020[23]	Performance, interpretation, and application of stress echocardiography in ischemic heart disease	ASE

EACVI: European association for cardiovascular imaging, ASE: American Society of Echocardiography, NORRE: Normal reference ranges for echocardiography (study), 3D: Three-dimensional, 2D: Two-dimensional

Minimal standard acquisition protocol for transthoracic echocardiography is necessary to acquire a complete exam, with the use of zoom options when necessary; in each view, a cine-loop or still frame is required, preferably while recording three consecutive cycles.[7] Table 2 shows the standard digital acquisition protocol, windows or modes, and the preferred still frame or loop to be acquired.

Table 2

Basic standard acquisition protocol; Evangelista et al.[7] with modification

View	Mode	Data type
PLAX/LV	2D, M-mode	Loop
PSAX/Ao	2D, CD, M-mode	Loop
PSAX/MV	2D	Loop
PSAX/PM	2D	Loop
PS RVIT	2D, CD	Loop
PS RVOT	2D, CD	Loop
A2C	2D, CD	Loop
A3C	2D, CD	Loop
A4C	2D, CD	Loop
A5C	2D, CD	Loop
SC 4C	2D, CD	Loop
SC IVC	2D, M-mode	Loop
SS LAX	2D, CD	Loop
Transmitral velocities	PWD (spectral)	Still frame
LVOT velocities	PWD (spectral)	Still frame
Transaortic velocities	CWD (spectral)	Still frame
Tricuspid regurgitant velocities	CWD (spectral)	Still frame
Transpulmonary velocities	PWD (spectral)	Still frame
Mitral annulus (septal, lateral)	TD (spectral)	Still frame

PLAX: Parasternal long axis, PSAX: Parasternal short axis, PS: Parasternal, A2C: Apical 2-chambers, A3C: Apical 3-chambers, A4C: Apical 4-chambers, A5C: Apical 5-chambers, SC: Subcostal, SS: Suprasternal, LVOT: Left ventricle outflow tract, LV: Left ventricle, MV: Mitral valve, PM: Papillary muscles: RVIT: Right ventricle inflow tract, RVOT: Right ventricle outflow tract, LAX: Long axis, IVC: Inferior vena cava, 2D: Two-dimensional, CD: Color Doppler, PWD: Pulsed wave Doppler, CWD: Continuous wave Doppler, TD: Tissue Doppler

Focused cardiac ultrasound (FOCUS) refers to examination performed in a specific clinical setting that is goal-oriented and is often performed with semi-portable or hand-held machines with limited capabilities.[2829] Contrary to FOCUS, limited echocardiogram refers to the performance of limited echo views even though there are full echocardiographic capabilities. FOCUS is often used in an emergency setting, namely, outside the formal echo laboratory (emergency room, intensive care unit, ambulance, or remote village, etc.) The approach may be referred to as point-of-care ultrasound (POCUS). Sometimes, these exams are labeled as Focused Echocardiographic Evaluation in Life support (FEEL), Focused Assessment with Transthoracic Echocardiography (FATE), Fast Assessment Diagnostic Echocardiography (FADE), or Focused critical care echocardiography (FCCE).[30]

For all these approaches, special attention must be kept for QA. In such a context, there is a real risk of misdiagnosis and misinterpretation of ultrasound images, especially that sonographers in these circumstances could be fellows, or physicians with limited proficiency in echocardiography. Validation of echo exams by certified echocardiographers is required whenever necessary. Images recording and storage must be performed as with formal echocardiography, for clinical, administrative, and medico-legal reasons. If needed, representative images which are paper-based could be re-captured digitally for archiving.[3132]

d. Reporting:

The report must bring the principal information to provide for both cardiologists and non-cardiologists, addressing the main clinical query, and emphasizing on abnormal findings, with a comparison with any previous exam, if any.

Table 3 shows the minimal data to be included in the heading of an echocardiography report. Characteristically, the report must include information on cardiac anatomy and function (namely LV structure and systolic function), also it should provide data on LV diastolic patterns and LV filling pressure. Similarly, information regarding left atrial structure, aorta, right ventricle structure and function, pulmonary artery pressure, pericardium, and valves structure and function is required.[7]

Table 3

Minimal data to be included in the report heading

Headings
Patient ID, name, location (inpatient or outpatient) and demographics
Gender, age (or date of birth), body weight, heart rhythm and rate, blood pressure
Date of study
Main clinical condition, main indication of the study
Name of attending physician and/or physician requesting the echo
Type of machine used
Exam conditions (patient compliance, image quality, regular or urgent exam, etc.)

Gardin et al.[33] with modification. ID: Identification

The report must be standardized, reporting both qualitative and quantitative data, including parameters acquired with advanced techniques (3D echo, DFI) for more relevant and comprehensive assessment.[33] Table 4 shows the quantitative data (with the normal values) that are recommended as standard parameters to be mentioned in a report.[34] These detailed quantifications should lead to a clear interpretation for objective communication between the sonographer and the recipient of the echo report. In addition, grading of qualitative parameters with the use of standardized terms, such as mild, moderate, or severe, is essential to determine the degree of any abnormality and to make appropriate managerial decisions.

Table 4

Quantitative data with the normal values; Values are rounded to the nearest whole number

Parameter	Normal values
LVEDD (mm)	≤58 (male), ≤52 (female)
LVEDV index (cc/m2)	<65 (male), <62 (female)
3D LVEDV index (cc/m2)	<80 (male), <72 (female)
LVESV (cc/m2)	<32 (male), <25 (female)
3D LVESV (cc/m2)	<33 (male), <29 (female)
LV mass index (g/m2)	≤102 (male), ≤88 (female)
LVEF (Simpson, %)	≥52 (male), ≥54 (female)
3D LVEF (%)	>54 (male), >57 (female)
LVGLS (%)	>20
Transmitral E/A ratio	>0.8, <2.0
LV septal annular velocity (E’, cm/s)	>7
LV lateral annular velocity (E’, cm/s)	>10
LAVI (cc/m2)	≤34
RV at the base (RVd1, mm)	<42
RV mid diameter (RVd2, mm)	<36
RVOT proximal diameter (mm)	<36
RVOT distal diameter (mm)	<28
TAPSE (mm)	>17
RV fractional area change (%)	>35
RV tricuspid annular velocity, S’ (cm/s)	>9.5
RAVI (cc/m2)	<30 (male), >28 (female)
Aortic annulus (mm/m2)	≤14 (male, female)
Aorta, sinus of Valsalva (mm/m2)	≤19 (male), ≤20 (female)
Aorta, sinotubular junction (mm/m2)	≤17 (male, female)
Aorta, proximal ascending (mm/m2)	≤17 (male), ≤19 (female)
RV free wall GLS (%)	>23

Adopted form Galderisi et al.[34] with modification. LVEDD: Left ventricle end-diastolic diameter, LVEDV: Left ventricle end-diastolic volume, LVESV: Left ventricle end-systolic volume, 3D: Three-dimensional, LVEF: Left ventricle ejection fraction, GLS: Global longitudinal strain, LAVI: Left atrial volume index, RV: Right ventricle, RVOT: Right ventricle outflow tract, TAPSE: Tricuspid annulus plane systolic excursion, RAVI: Right atrium volume index, LV: Left ventricle, LVGLS: Left ventricular global longitudinal strain

The conclusion of the report must be concise and conclusive, including mostly qualitative rather than quantitative data, also reporting on abnormal findings and addressing the main exam request and pathology in a given patient, also it shall be clinically oriented toward the management of the patient condition.[34]

e. Storage and archiving:

Digital storage of echocardiograms offers high-quality data archiving and does not carry a significant risk of degradation over time, as compared to analog storage (video storage). Digital storage allows for better accessibility, and it is more convenient especially for data retrieval and for displaying options. In addition, digital storage usually allows higher memory capacity, especially for a busy echo laboratory that requires huge demands for memory space. Of note, clinical compression (selection of representative images and cine-loops in each view) is helpful to preserve storage capacity.

Echocardiography data storage is usually connected to the facility storage network, allowing secure transmission and retrieval of patient information, images, loops, and reports from allocated workstations.

All studies should be recorded and stored for subsequent retrieval, analysis, and review; studies that are not stored may not be reimbursed, also they may lead to conflicts in case of potential medico-legal issues. Periodic equipment servicing, regular data backup, and other safety measures against data loss and for protection against unauthorized use are mandatory.[67]

QUALITY IMPROVEMENT PROCESS

QI should be set up to preserve quality in the first place, and to improve the quality regularly in a continuously changing domain (advanced equipment, new techniques, medical progress, etc.). QI plan implies regular monitoring and managing of every detail in the echocardiography laboratory in order to optimize performance within a structured framework of strategic planning with timeline and metrics to assess outcome [Figure 1]. Optimally, any QI plan is set up among peers in the echocardiography laboratory (peer committee), and it is advised to be reviewed and re-assessed regularly (e.g., quarterly or biannually). Such a process cannot take place without interactive and constructive communication among sonographers within the same echocardiography laboratory, also the role of the echo laboratory manager (if any) is crucial in this regard.

Figure 1

General framework for quality improvement and strategic planning

The main issues to be addressed in the context of QI plan comprise the enhancement of conformity with appropriate use criteria and standardization, timely completion of exams and reports, detection and management of discrepancies, improvement of knowledge and skills along with managerial, and organizational functions [Figure 2].[3536]

Figure 2

Figure showing the main components of a quality improvement project which must be set up and implemented by the peer committee. AUC: Appropriate use criteria

a. Adherence to appropriate use criteria:

Adherence to appropriate use criteria is essential to implement an efficient QI plan. Sensitization of cardiologists in this regard is of utmost significance to conform with appropriate use criteria (i.e., regular lectures, placement of relevant posters in Echo laboratory and medical staff meeting room, emails, use of web-based educational program using an electronic application, etc.). Of note, performing regular auditing with feedback providing metrics is essential for improving conformity with appropriate use criteria.[9]

b. Conformity with standardization:

Conforming to standards regarding echocardiography practice is crucial, and QI plan should always aim to enhance the standardization of assessment methods and reporting.

Accurate assessment of cardiac structures, function, and hemodynamics is classically the primary objective in any echocardiography laboratory. In this regard, it is essential to use updated equipment, implement optimal technical settings, implement advanced ultrasonographic modes (i.e., 3D echo, DFI) whenever feasible for accurate data acquisition and comprehensive interpretation. Auditing of the peer committee is supposed to detect potential lack in standardization, and accordingly, the peer committee is expected to report (quarterly or bi-annually) to sonographers potential deficiencies regarding standardization, with specific and consistent suggestions for improvement.[3637]

c. Procedural volume, time, and duration:

Quality relates not only to how echocardiography exams are performed, but also to when and with how much duration or delays.

Timely performance of emergencies (during or outside regular schedule) is crucial, also many other parameters may be checked, reported, and then addressed for improvement: exam request to exam performance duration, average exam duration (per operator), exam to completion of report duration, and exam to digital storage duration.[35]

Echocardiography laboratory volume is an essential key parameter to adjust patients' circulation in the echo unit, also it is important for staffing and shift administration and scheduling. Moreover, procedural volume per operator is an important index to monitor, knowing that excessively low or high procedural volume per operator may affect quality.[35]

One of the common consequences of an overloaded echocardiography laboratory is the long waiting list for appointments and the accumulation of unfinished reports; this fact may affect quality owing to the significant delay between study request and study performance or reporting, with consecutive delay to access essential information for patient management.[35] Regular auditing with active interventions allows to address and fix any significant delays in this regard.

d. Variabilities and addressing discrepancies:

Variabilities in echocardiography laboratories are common, especially that sonographers may have different scientific backgrounds and different levels of expertise. Classically, when variability is minimal, it can be considered physiological; however, when it is significant, it is rather designated as inconsistency or discrepancy and should be addressed for quality issues.[38]

Many factors are involved in the exam variability which may be observed as intra-observer or inter-observer phenomenon. Variability could be operator dependent (experience and skills, methods used, measurement inaccuracy, etc.), machine-dependent (machine from different vendors, use of a machine with limited capabilities), or patient dependent (poor sonographic signal, patient status changes, etc.).[394041]

Auditing allows to detect variability, and a consistent QI program managed by the peer committee should undertake a reasonable approach to address discrepancies while focusing on standardization, also a learning program may be set up via the peer committee in this regard (conferences, e-mails, posters, etc.).[42]

Of note, common echocardiographic parameters subject to discrepancies are LV end-diastolic volume, LV ejection fraction, LV mass, pulmonary artery pressure, right atrial pressure, diastolic dysfunction diagnosis, and grading.[3739]

e. Advanced cardiac sonographers, continuous improvement of knowledge, and skills:

Adherence to best practices in image acquisition and interpretation should be the hallmark of proficiency, with the main objective being a patient-centered result for better clinical outcomes.

Besides the initial formal certification and training, continuous updating of knowledge and skills is required in a rapidly changing domain, with the continuous emergence of new echo techniques and applications.[43] Inaccuracy in echocardiography analysis and interpretation are relatively prevalent and is often associated with conflicting outcome; such instances may be occasional resulting from physician fatigue or inattention. Importantly, the use of new technology should be preceded by consistent knowledge and appropriate technical training.[4445]

Qualified cardiac sonographer is expected to have an advanced professional level, to be well trained to acquire proper structural, physiological, and hemodynamic echo data and to put all together in a logical conclusion to establish an accurate echo diagnosis for clinical decision-making and management.[2]

Of note, advanced cardiovascular sonographer is expected to assist other sonographers when needed, and this approach would improve the quality of the examinations and bring advancements in echocardiographic methods which could be taught and incorporated into daily practice for better clinical outcome.[464748] Figure 3 shows parameters and related issues with the different levels of proficiency and skills in cardiac sonography.[4950515253]

Figure 3

The three different levels of proficiency and skills in cardiac sonography.[4950515253] FADE: Fast assessment diagnostic echocardiography, FEEL: Focused echocardiography entry-level, FCCE: Focused critical care echocardiography, POCUS: Point-of-care ultrasound, FOCUS: Focused cardiac ultrasound, DFI: Deformation imaging, 3D echo: Three-dimensional echo, QA: Quality assurance, QI: Quality improvement

f. Managerial, educational, and ethical issues:

Professionalism in healthcare facilities is a minimal requirement, namely, in echocardiography, the organizational, and managerial function is essential to ensure QA and QI, with checklist and metrics of quality (do-or-die process).

QA and QI are optimally planned by the peer committee, which might comprise the echo laboratory manager (if any) and the medical director. The peer committee is expected to approve and ensure implementation of the QI project within a timetable in order to evaluate results and to apply corrective measures.[7] The peer committee has to monitor and manage the roadmap of any QI project, from plan to action, aiming to identify and address any potential deficiency in the echocardiography laboratory while targeting a patient-centered continuous evolutionary project.[54]

g. Training, teaching, research:

In most echo laboratories, there are often different sonographers with variable degrees of training and experience for performing and interpreting exams; besides, there are sometimes some entry-level sonographers who may not have sufficient practical or clinical knowledge, also they may work independently without supervision.[54] The need for appropriate education, training, and certification of sonographers, fulfilling a formal curriculum, is a minimum requirement to be qualified as echocardiographer.[4654]

Engaging in research, teaching, and training of juniors is also a task of advanced cardiac sonographers, they may use all available technology for this purpose, in order to well prepare the next generation with supervision and systematic quality checking.[5556]

h. Internal auditing and accreditation:

Auditing, whether internal (i.e., peer committee, auditing committee) or external (i.e., accreditation organizations), allows for identifying potential deficiencies in the echocardiographic process, starting from the indication, through performance and interpretation till reporting and archiving.[5758] Besides, auditing allows putting a framework as the basis for a QI program, in order to enhance all components of the echocardiographic process, with a persistent focus on a patient-centered plan.[59]

Passive auditing is performed through the registry system; however, active internal auditing and QI meetings should be held quarterly or as needed, among the peer committee members and with the supervision of the medical director to discuss findings and to set up a timetable plan for improvement in a form of strategic planning.

i. Relational and ethical issues:

The peer committee (and the affiliated sub-committees) must be capable of gathering, processing all necessary data, including budget and reimbursement issues, to ensure best practice and to improve quality in the echocardiography laboratory. In this regard, it is recommended to use objective qualitative and quantitative indices (metrics) to evaluate echocardiography laboratory performance.[248]

Many of the tasks of the medical director could be deputized to the echo laboratory manager (if any); however, not all institutions are organized in a way to assign a manager or director to the echocardiography unit. The unit manager (if applicable) may play a crucial role in this regard, with a unifier profile based on equity, ethics, professionalism, and teamwork.[60] Of note, the medical director is supposed to update administrative regulations, in order to ensure the allocation of appropriate geographical space for the echocardiography laboratory, obtainability of adequate and updated equipment, enhancement of teamwork, and allocation of high-quality paramedical assistance (nursing, secretaries, etc.), while ensuring professional standards.

CONCLUSION

QA is correlated to appropriate use criteria, appropriate equipment, standardization of performance and reporting, storage, and archiving. QI aims to enhance conformity with appropriate use criteria and standards, ensure timely completion of exams and reporting, detection and management of discrepancies along with continuous improvement of knowledge and skills.

QI based on strategic planning aims to promote high-quality echocardiogram, with endorsement of education, training, and research in a rapidly evolving domain. A peer committee must be able to gather essential and accurate information about the echo laboratory in order to better organize and prioritize issues leading to a better quality of care. Moreover, teamwork enhances better communication which facilitates effective collaboration among sonographers, based on ethics and equity, while focusing on a patient-centered QI project that is safe and efficient.

Footnote

The echocardiography approach and related discussion used in this paper mainly address echocardiography in adults, and many data may not be applicable for pediatric echocardiography. In some medical literature or healthcare institutions, the use of the term “cardiac sonographer” is meant to be the operator who perform the cardiac echo exam, without being necessarily a physician or cardiologist; in this article, the terms “sonographer” or “echocardiographer” are all meant to be a cardiologist with expertise in echocardiography, including performance, interpretation and reporting.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.