SPECIAL SECTION: ACC/AHA CLINICAL COMPETENCE STATEMENT
ACC/AHA clinical competence statement on echocardiography1 ,2 ,*
A Report of the American College of Cardiology/American Heart Association/American College of Physicians–American Society of Internal Medicine Task Force on Clinical Competence Developed in Collaboration with the American Society of Echocardiography, the Society of Cardiovascular Anesthesiologists, and the Society of Pediatric Echocardiography
Miguel A. Quiñones, MD, FACC, Chair, Writing Committee Member,
Pamela S. Douglas, MD, FACC, FAHA, Writing Committee Member,
Elyse Foster, MD, FACC, FAHA, Writing Committee Member,
John Gorcsan, III, MD, FACC, FAHA, Writing Committee Member,
Jannet F. Lewis, MD, FACC, FAHA, Writing Committee Member,
Alan S. Pearlman, MD, FACC, FAHA, Writing Committee Member,
Jack Rychik, MD, FACC, Writing Committee Member,
Ernesto E. Salcedo, MD, FACC, Writing Committee Member,
James B. Seward, MD, FACC, Writing Committee Member,
J. Geoffrey Stevenson, MD, FACC, Writing Committee Member,
Daniel M. Thys, MD, FACC, FAHA, Writing Committee Member,
Howard H. Weitz, MD, FACC, Writing Committee Member,
William A. Zoghbi, MD, FACC, FAHA, Writing Committee Member,
Mark A. Creager, MD, FACC, Chair Task Force Member,
William L. Winters, Jr, MD, MACC, FAHA, Immediate Past Chair Task Force Member*,
Michael Elnicki, MD, FACC, FACP, Task Force Member,
John W. Hirshfeld, Jr, MD, FACC, FAHA, Task Force Member,
Beverly H. Lorell, MD, FACC, FAHA, Task Force Member,
George P. Rodgers, MD, FACC, Task Force Member,
Cynthia M. Tracy, MD, FACC, FAHA, Task Force Member and
Howard H. Weitz, MD, FACC, FACP, Task Force Member
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Table of contents
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Preamble......688 - Introduction......689
Purpose of this Clinical Competence Statement......689
Document Format......689
- General Principles......689
Basic Knowledge of Ultrasound Physics......690
Technical Aspects of the Examination......690
Anatomy and Physiology......690
Recognition of Simple and Complex Pathology......690
- Transthoracic Echocardiography in Adult Patients......690
Overview and Indications for the Procedure......690
Minimum Knowledge Required for Performance and Interpretation......690
Training Requirements......691
Proof of Competence......692
Board Examination......693
Certification......693
Maintenance of Competence......693
- Transeophageal Echocardiography......693
Overview and Indications for the Procedure......693
Minimum Knowledge Required for Performance and Interpretation......693
Training Requirements......694
Proof of Competence......695
Maintenance of Competence......695
- Perioperative Echocardiography......696
Overview and Indications for the Procedure......696
Minimum Knowledge Required for Performance and Interpretation......696
Training Requirements......696
Proof of Competence......698
Maintenance of Competence......699
- Stress Echocardiography......699
Overview and Indications for Procedure......699
Minimum Knowledge Requirements for Performanceand Interpretation......699
Training Requirements......699
Proof of Competence......699
Maintenance of Competence......700
- Echocardiography for CHD Patients......700
Overview and Indications for Procedure......700
Minimum Knowledge Required for Performance and Interpretation......701
Technical Aspects of the Examination......701
Anatomy and Physiology......702
Recognition of Simple and Complex Pathology......702
Training Requirements......702
Proof of Competence......702
Maintenance of Competence......703
- Fetal Echocardiography......703
Overview and Indications for Procedure......703
Minimum Knowledge Required for Performance and Interpretation......703
Training Requirements......704
Proof of Competence......705
Maintenance of Competence......705
- Emerging New Technologies......705
- Hand-Carried Ultrasound Devices......705
Overview and Indications for the Procedure......705
Minimum Knowledge Required for Performance and Interpretation......706
Training Requirements......706
Proof of Competence......706
Maintenance of Competence......706
- Contrast Echocardiography......706
Overview and Indications for the Procedure......706
Minimum Knowledge Required for Performance and Interpretation......706
Training Requirements......706
Proof and Maintenance of Competence......706
- Intracoronary and Intracardiac Ultrasound......706
Overview and Indications for the Procedure......706
Minimum Knowledge Required for Performance and Interpretation......707
Training and Competence Requirements......707
- Echo-Directed Pericardiocentesis......707
Overview and Indications for the Procedure......707
Minimum Knowledge Required for Performance and Interpretation......707
Training Requirements......707
Maintenance of Competence......707
References......708
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Preamble
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The granting of clinical staff privileges to physicians is a primary mechanism used by institutions to uphold the quality of care. The Joint Commission on Accreditation of Health Care Organizations requires that the granting of continuing medical staff privileges be based on assessments of applicants against professional criteria specified in the medical staff bylaws. Physicians themselves are thus charged with identifying the criteria that constitute professional competence and with evaluating their peers accordingly. Yet, the process of evaluating physicians’ knowledge and competence is often constrained by the evaluator’s own knowledge and ability to elicit the appropriate information, problems compounded by the growing number of highly specialized procedures for which privileges are requested.
The American College of Cardiology/American Heart Association/American College of Physicians–American Society of Internal Medicine (ACC/AHA/ACP–ASIM) Task Force on Clinical Competence was formed in 1998 to develop recommendations for attaining and maintaining the cognitive and technical skills necessary for the competent performance of a specific cardiovascular service, procedure, or technology. These documents are evidence-based, and when evidence is not available, expert opinion is utilized to formulate recommendations. Indications and contraindications for specific services or procedures are not included in the scope of these documents. Recommendations are intended to assist those who must judge the competence of cardiovascular health care providers entering practice for the first time and/or those who are in practice and undergo periodic review of their practice expertise. The assessment of competence is complex and multidimensional; therefore, isolated recommendations contained herein may not necessarily be sufficient or appropriate for the judging of overall competence.
The ACC/AHA/ACP–ASIM Task Force makes every effort to avoid any actual or potential conflicts of interest that might arise as a result of an outside relationship or personal interest of a member of the ACC/AHA Writing Committee. Specifically, all members of the Writing Committee are asked to provide disclosure statements of all such relationships that might be perceived as real or potential conflicts of interest. These changes are reviewed by the Writing Committee and updated as changes occur.
Mark A. Creager, MD, FACC,
Chair, ACC/AHA/ACP-ASIMTask Force on Clinical Competence
A. Introduction.
This document is a revision of the 1990 ACP/ACC/AHA Clinical Competence in Adult Echocardiography (1). The writing committee consisted of recognized experts in echocardiography representing the ACC, AHA, ACP–ASIM, American Society of Echocardiography (ASE), Society of Pediatric Echocardiography (SOPE), and the Society of Cardiovascular Anesthesiologists (SCA). The document has been approved for publication by the governing bodies of the ACC and the AHA, and endorsed by the ASE, SCA, and SOPE.
Purpose of this clinical competence statement
Previous publications have focused on training requirements for clinical competence in echocardiography. The first recommendations were made in 1986 by Bethesda Conference 17: Adult Cardiology Training (2) and in 1987 by an expert panel of the ASE (3). They were followed by a previous version of the ACP/ACC/AHA physician clinical competence statement in 1990. These earlier recommendations were limited primarily to the practice of transthoracic echocardiography (TTE) in the adult patient. However, over the past 15 years echocardiography has evolved into a family of techniques (Table 1), each one with unique applications and its own set of cognitive skills and training requirements. Although the majority of these newer technologies were in their early phase of development in 1990, today they are used routinely in community hospitals all across the nation. In addition, the application of echocardiography in children and adults with congenital heart disease (CHD) has evolved into a highly specialized modality with its own set of cognitive skills and training requirements. Subspecialty societies such as the ASE have published recommendations for training and, in some cases, for competence in some of these newer techniques. In addition, guidelines for training in adult cardiovascular medicine in the form of a suggested core curriculum (COCATS) have included recommendations on training in echocardiography, first in 1995 and currently in a revised version (4). The recently formed National Board of Echocardiography (NBE) has also introduced guidelines for certification of special competence in adult echocardiography, which includes passing an examination in addition to specific training requirements. Separate certifications are granted for transesophageal echocardiography (TEE) and stress echocardiography. Recognizing the growths in technology and the increased complexity of echocardiography, the members of the ACC/AHA/ACP–ASIM Task Force on Clinical Competence commissioned this writing group to provide a new set of recommendations that recognize the different cognitive skills required for each of the new modalities and that address training, documentation and maintenance of competence.
Document format
This document addresses competence in the performance and interpretation all the different modalities of echocardiography, including new applications of echocardiography in the operating room and the application of echocardiography in patients with complex CHD. The document also addresses the application of echocardiography using miniaturized hand-carried ultrasound instruments. For each of the applications, there will be a brief general overview, a discussion of the cognitive skills required and recommendations on training requirements, proof of competence, and maintenance of competence. Whenever possible, these recommendations will be linked to previously published recommendations made by specialty societies. In some situations, however, the writing group provides a set of recommendation that represent the consensus of this body of experts.
This document makes an important distinction between training requirements and documentation of competence. Training requirements represent the minimal training experience that is considered necessary to achieve the skills for performance at a particular level. It is recognized that training is highly individualized and some trainees may require higher volume and more hours of exposure to a particular technique. Proof of competence, on the other hand, consists of a set of requirements that provide some assurance that physicians have gained the expertise needed to perform according to recognized standards.
The sections on training requirements refer primarily to the training needed to achieve specific levels of expertise. Such training is expected to occur under the direct supervision of a qualified Level 3 or equivalent physician/teacher and for the most part, occurs during formal fellowship training in either cardiovascular medicine or cardiovascular anesthesiology. However, the document recognizes the fact that physicians trained prior to the development of these techniques may have properly learned their use while in practice. Thus, whenever possible, the document addresses training requirements and proof of competence for this group of physicians. Maintenance of competence requires the performance of a certain minimal volume of procedures and participation in continuing medical education (CME). This document recommends that physicians practicing echocardiography obtain a minimum of 5 hours per year of CME credits in echocardiography, as recommended recently by the Intersocietal Commission for the Accreditation of Echocardiography Laboratories (ICAEL Newsletter 2001Vol 4; Issue 2; page 5).
B. General principles.
Regardless of the echocardiographic modality utilized, there is a body of knowledge required by any physician involved in performance and/or interpretation of echocardiograms that includes: ultrasound physics and use of instrumentation, anatomy, physiology, and pathology of the heart and great vessels (Table 2).
Basic knowledge of ultrasound physics
Echocardiographic imaging and Doppler systems generate ultrasound signals that follow the laws of physics. Appropriate utilization of these instruments and interpretation of the data generated require an understanding of the fundamental principles of ultrasound physics and how they relate to the images produced and the spectral and color Doppler information. This understanding is considered to be an important requirement for clinical competence in all modalities of echocardiography.
Technical aspects of the examination
An essential component of the diagnostic accuracy of echocardiography is the skill and experience of the individual responsible for image and data acquisition. Technical skills related to echocardiographic data acquisition may be divided into two important skill sets: transducer manipulation and ultrasound system adjustments. Perhaps the most difficult and underestimated skill set to master is transducer manipulation, which is critical to obtaining optimal image quality in standard tomographic imaging planes, and optimal Doppler flow velocity signals. This is true regardless of the type of transducer utilized (i.e., transthoracic, transesophageal, or intravascular). The second set of technical skills includes appropriate knowledge of ultrasound instrument settings such as transducer frequency, use of harmonics, mechanical index, depth, gain, time-gain-compensation, dynamic range, filtering, velocity scale manipulations, and display of received signals.
Anatomy and physiology
Echocardiography is a powerful diagnostic tool that provides immediate access for the evaluation of cardiac and vascular structures and assessment of heart function. Intrinsic to a competent echocardiographic examination is a thorough understanding of the anatomy and physiology of the heart and great vessels. Two-dimensional imaging can accurately quantify cardiac chamber sizes, wall thickness, ventricular function, valvular anatomy, and great vessel size. Pulsed, continuous-wave, and color-flow Doppler echocardiography, especially when combined with two-dimensional imaging, can be used to quantify blood flow velocities and calculate blood flow; assess intracardiac pressures and hemodynamics; and detect and quantify stenosis, regurgitation, and other abnormal flow states. Documentation of normal and abnormal cardiac anatomy and physiology must be accomplished by the individual performing the examination.
Recognition of simple and complex pathology
The ability to recognize both simple and complex pathology of the heart and great vessels is required for competence in echocardiography. A fundamental knowledge of cardiac pathology is required during data acquisition to tailor the examination appropriately and maximize demonstration of the abnormalities present. This includes the ability to modify standard imaging planes and optimize the Doppler beam angle of incidence to achieve this goal. In addition, an extensive knowledge of pathology and pathophysiology is required to interpret recorded echocardiographic data.
C. Transthoracic echocardiography in adult patients.
Overview and indications for the procedure
Transthoracic two-dimensional and Doppler echocardiography is one of the most important and frequently performed diagnostic procedures for patients with cardiovascular disease. It provides highly accurate diagnostic information regarding the anatomy and physiology of the cardiac chambers, valves, major vessels, and pericardium in a noninvasive and instantaneous manner. This information can immediately affect the further diagnostic work-up for the patient, dictate therapeutic decisions, determine response to therapy, and predict patient outcome. Because transthoracic two-dimensional/Doppler echocardiography plays such a major role in the care of patients with suspected or known cardiovascular diseases, the widely accepted indications for the procedure span the breadth of cardiovascular medicine, including but not limited to the diagnosis of and guiding treatment for: coronary artery disease, valvular heart disease, heart failure, hypertensive heart disease, congenital abnormalities, complications of pulmonary disease, tumors/masses, cardiac trauma, pericardial disease, and others. Details of accepted indications have been recently revised (ACC/AHA Guidelines revision, publication pending). This section will discuss the cognitive requirements, training, proof of competence, and maintenance of competence for performance and/or interpretation of TTE in adult patients with acquired diseases and/or simple congenital heart defects. A separate section is dedicated to the use of echocardiography in pediatric patients and adults with complex congenital defects, as defined by the Task Force 1 Report from the 32nd Bethesda Conference on "Care of the Adult with Congenital Heart Disease" (5). Simple lesions are listed in Table 3.
Minimum knowledge required for performance and interpretation (Table 4).
Competence in performing and/or interpreting TTE in adult patients requires all of the basic knowledge of ultrasound physics, of instrumentation, and of cardiac anatomy, physiology and pathology described in the section on General Principles. Transducer manipulation is perhaps the most difficult and underestimated skill set to master when performing a transthoracic echocardiographic examination. It is the most important factor in obtaining optimal image quality in standard tomographic imaging planes and optimal Doppler flow velocity signals. As previously mentioned, appropriate knowledge of ultrasound instrument settings such as depth, gain, time-gain-compensation, dynamic range, filtering and display of received signals is essential for performing an optimal examination. Even though the majority of echocardiographic examinations are performed by sonographers and interpreted by physicians in most clinical settings in the United States, all physicians interpreting scans are required to be skilled in echocardiographic data acquisition as well. This facilitates the physician’s understanding of optimal echocardiographic data acquisition and technical quality. Physicians who are ultimately responsible for the diagnostic data should play an appropriate role in quality control and teaching in the sonographer-physician relationship. The echocardiographic physician should accordingly be available for consultation with the sonographer. Furthermore, a physician properly trained in echocardiographic data acquisition should be able to perform emergency bedside echocardiographic examinations when a sonographer is not available.
Training requirements (Table 5)
Training in adult TTE remains intimately linked to training in other aspects of adult cardiovascular medicine, including cardiovascular catheterization, inpatient and outpatient clinical care, electrocardiography, pacing and electrophysiology, cardiac surgery, and other noninvasive imaging. The number of procedures required to accomplish clinical competence in two-dimensional Doppler echocardiography is, in reality, somewhat arbitrary because there is individual variation in cognitive, analytical, and manual-dexterity skills. Furthermore, the breadth of the clinical experience is equally as important as the numbers themselves, in that supplemental training may be required in centers where patient populations are skewed by specific referral patterns. It is important to emphasize that the numbers of examinations refer to comprehensive two-dimensional and Doppler echocardiographic studies that are diagnostic, complete, and quantitatively accurate.
The numbers set forth in this document reflect the minimum requirements for the average trainee engaged in a training program in adult cardiovascular medicine. These numbers have been revised specifically to reflect the reality of mainstream training programs in cardiovascular medicine in the current era. A new distinction has been made between the performance of echocardiograms and interpretation of echocardiograms. Expert consensus remains that all physicians involved in the practice of the subspecialty of cardiovascular medicine or who participate in interpreting echocardiograms must be trained at a minimum level in performing echocardiograms (Table 5).
Level 1 Training (3 months, 75 examinations performed, 150 examinations interpreted). Level 1 is defined as the minimal introductory training that must be achieved by all trainees in adult cardiovascular medicine. This includes a basic understanding of the physics of ultrasound, the fundamental technical aspects of the examination, cardiovascular anatomy and physiology as it relates to echo and Doppler imaging, and recognition of simple as well as complex cardiac pathology and pathophysiology. Level 1 trainees are required to train in echocardiography for a minimum of three months and perform and interpret a minimum of 75 two-dimensional and Doppler TTEs, and interpret an additional 75 two-dimensional and Doppler TTEs (total of 150 exams interpreted). This nominal hands-on training should enable a physician to expand on or clarify the data acquired by a sonographer, and to understand potential technical limitations and artifacts. Level 1 training is not sufficient for a trainee to perform or interpret echocardiograms independently.
Level 2 Training (6 months, 150 examinations performed [75 additional] and 300 interpreted [150 additional]. Level 2 training is the minimum recommended training for a physician to perform and interpret echocardiograms independently. These requirements are specifically for transthoracic two-dimensional and Doppler echocardiography. Level 2 is defined as a minimum of an additional 3 months of training in echocardiography (6 months cumulative) and the addition of 150 transthoracic two-dimensional and Doppler examinations interpreted (300 cumulative exams interpreted). Additional training in special procedures, such as TEE and stress echocardiography, is detailed subsequently in this document. Although some experience in special procedures may be attained as a part of Level 2 training, in most instances, full competence in these areas will require additional training beyond Level 2.
Level 3 Training (12 months, 300 transthoracic two-dimensional and Doppler echocardiograms performed [150 additional] and 750 interpreted [450 additional]). Level 3 represents a high level of expertise that would enable an individual to serve as a director of an echocardiography laboratory and be directly responsible for quality control and for the training of sonographers and physicians in echocardiography. Although these guidelines reflect the minimum number of TTE and Doppler studies, most physicians who are Level 3-trained will also have additional training in TEE and stress echocardiography. It should be emphasized that these numbers reflect the minimum examinations considered for clinical competence; many training programs will offer a greater experience in interpretation of transthoracic echocardiograms over the time periods previously outlined.
Physicians who trained in Cardiovascular Disease before July 1990 (when the Level 1 to 3 guidelines were adopted) are considered clinically competent for independent performance and interpretation if they have either the equivalent of Level 2 training, as previously set forth, or have the experience of providing echocardiographic services for a minimum of 400 examinations performed and/or interpreted per year for a minimum of 3 years. Physicians who completed training in Cardiovascular Disease between July 1990 and July 1998 are considered clinically competent in echocardiography with the equivalent of Level 2 training, as previously set forth, if they completed 3 months training in echocardiography with performance and interpretation of 150 transthoracic echocardiograms, and have provided echocardiographic services of a minimum of 400 echo and Doppler examinations per year for a minimum of 2 years. Physicians who completed training in Cardiovascular Disease after July 1998 can be considered clinically competent in echocardiography with 6 months of training, a minimum of 150 examinations performed and a total of 300 examinations interpreted.
Proof of competence (Table 6)
The optimal evaluation of clinical competence is performed by an individual or individuals who observe the trainee directly. This is usually accomplished by the director of the echocardiography laboratory or by qualified faculty who participate in the training activities of the laboratory. Trainees are strongly encouraged to maintain a log with counts of all performed and interpreted echocardiograms that should be updated regularly. A letter or certificate from either the supervising echocardiography laboratory director or the training program director, with input from the echocardiography laboratory director, should document both the duration of training and the counts of performed and interpreted echocardiograms at the end of their training program (Table 6).
In addition to the training requirements outlined in the foregoing text, proof of competence for individuals trained before 1990 may be established in one of the following three ways: 1) NBE Board Certification; 2) active participation by the physician in a laboratory accredited by the Intersocietal Commission for the Accreditation of Echocardiography Laboratories (ICAEL), with demonstration that the physician interprets a minimum of 300 studies per year, or 3) Endorsement by a Level 3-trained physician who has overread a minimum of 25 examinations interpreted by the individual. This Level 3-trained echocardiography physician may be either on-site or off-site in circumstances where a Level 3-trained physician is not available on-site.
Board examination
The NBE was formed in December of 1998 to establish criteria for Special Competence in Adult Echocardiography. These requirements include the successful completion of a written board examination for Special Competence in Adult Echocardiography, known as the ASCeXAM, and the completion training requirements consistent with this statement and the COCATS document.
Certification
The NBE has established a process to issuing certification for Special Competence in Adult Echocardiography, specifically in transthoracic two-dimensional and Doppler echocardiography, to physicians who have successfully completed all training requirements and have passed the ASCeXAM. Specific details regarding certification are offered on the NBE web site: www.echoboards.org.
Maintenance of competence (Table 6)
Clinical competence in echocardiography requires continued maintenance of skills in two-dimensional and Doppler echocardiography. Upon completion of the training requirements as previously discussed, a minimum of performance and/or interpretations of 300 examinations per year are required to remain proficient in providing echocardiographic services at Level 2. Because Level 3 skills include the supervision and education of sonographers and physicians training in echocardiography, maintenance of these skills requires physicians to perform and/or interpret a minimum of 500 transthoracic echocardiograms annually. In addition, it is essential that Level 3 physicians maintain their skills by performing transthoracic examinations. This can be done by periodically assisting the sonographers with the performance of more complex cases. Continuing medical education in echocardiography is essential to keep pace with ongoing technical advances, refinements in established techniques, and applications of new methods. Although minimal guidelines for CME are outlined in Section A, it is recommended that Level 3 physicians exceed these minimal standards so that they can remain as true experts in echocardiography. A program for continuous quality improvement in echocardiography should be employed as outlined in the ASE Continuous Quality Improvement document (6).
D. Transesophageal echocardiography.
Overview and indications for the procedure
Transesophageal echocardiography provides an excellent window for examining the heart and great vessels. Its clinical applications include, but are not limited to: detection and assessment of endocarditis and its complications, aortic dissection and other aortic pathologies, intracardiac thrombi and other masses, evaluation of valvular disorders including prosthetic valve function, and evaluation of a variety of CHDs in both children and adults. Transesophageal echocardiography is also of great use in patients with suspected cardiac trauma, in critically ill medical or surgical patients with unstable hemodynamics, and in patients whose clinical status necessitates echocardiographic assessment but in whom TTE studies are technically inadequate or non-diagnostic. In many large echocardiography laboratories, TEE studies represent between 5% and 10% of the total volume of echocardiographic examinations.
Transesophageal echocardiography is a minimally invasive procedure with small but definite risks (7). Therefore, it should be reserved for clinical circumstances in which the potential findings have significant implications for patient management and cannot be obtained by transthoracic evaluation.
Minimum knowledge required for performance and interpretation (Table 7)
Competence in performing and interpreting TEE in adult patients requires all of the basic knowledge of ultrasound physics and instrumentation as well as the cardiac anatomy, physiology, and pathology described in the section on General Principles. The specific cognitive and technical skills needed to perform TEE in a competent manner are listed in Table 7 (8).
Transesophageal echocardiography requires the insertion of an endoscopic probe into the esophagus and manipulating the probe through multiple imaging planes to obtain tomographic views of the heart and great vessels. To reduce the level of discomfort associated with the procedure, a topical anesthetic spray is administered to the oropharynx, and intravenous conscious sedation is often used. Consequently, the physician performing a TEE must be knowledgeable with regard to: pharyngeal and esophageal anatomy; the proper use of conscious sedation, including the prompt recognition of possible complications; the various techniques of esophageal intubation and probe manipulation; the recognition and management of possible complications of probe insertion, including the infrequent occurrence of methemoglobinemia as a complication of benzocaine administration; and the absolute and relative contraindications to the performance of a TEE examination. The operator must also have the necessary technical knowledge required to operate the ultrasound machine. Importantly, the physician performing a TEE needs good communication skills in order to explain the TEE procedure to patients in simple terms, including its risks, benefits, and alternative approaches—and in order to obtain the patient’s cooperation during the examination. In many patients, the results of a TEE examination guide urgent and definitive treatment (such as emergency surgery in a patient with an ascending aortic dissection); thus, the physician performing a TEE needs to have a thorough knowledge of cardiovascular disorders and their accompanying hemodynamic alterations, the different diagnostic issues that require consideration given a particular clinical presentation, and the potential therapies available. The operator also needs to have mastered a thorough understanding of the basic principles of ultrasound imaging and Doppler hemodynamic assessment described in detail in the previous sections.
Although it is usually preferable to perform a comprehensive and systematic TEE examination, it is not always possible, particularly in critically ill patients. Consequently, it is essential that the operator evaluate the most pressing diagnostic issues first. Therefore, the physician performing a TEE must be able to review available clinical and diagnostic information, including data from the TTE, in order to prioritize the most relevant issues and focus the TEE examination on resolving these issues.
Training requirements (Table 8)
The proper performance and interpretation of the TEE examination requires training in a number of elements such as: appropriate use of sedatives, proper and safe introduction of the TEE probe, manipulation of the TEE transducer, optimization of the echocardiographic instrument, correct interpretation of the study findings, and communication of findings to other healthcare providers in an articulate and effective manner. This training is best obtained during a formal fellowship in cardiovascular medicine, or its equivalent, and through active participation in a training program in general TTE. Alternatively, the training can be achieved as part of a cardiovascular anesthesiology or critical care medicine fellowship, with a formal period of intensive education in an affiliated diagnostic echocardiography laboratory.
Specifically, trainees must perform esophageal intubations (using a diagnostic TEE probe) under the tutelage of an experienced physician with advanced skills in TEE or under the supervision of an experienced endoscopist. Trainees must also perform a number of TEE examinations under the tutelage of an experienced TEE operator before performing TEE examinations independently. It is crucial that trainees learn to recognize normal and abnormal findings "on-line" and to manipulate the probe to obtain optimal views for evaluating the abnormalities observed. Because the results of a TEE examination are frequently considered "definitive" and used to make immediate and important management decisions, we do not believe in defining different levels of competence. Therefore, in regard to TEE, "minimum training" and "optimal training" are the same. We endorse the previously published recommendations of the ASE (8) and the ACC (4).
For physicians in formal cardiology fellowship training programs, training in TEE should include 1) attainment of at least Level 2 experience in general TTE; 2) performance of approximately 25 esophageal intubations with a TEE probe; and 3) performance of approximately 50 diagnostic TEE examinations under the supervision of an experienced (Level 3) echocardiographer, including the review, interpretation, and reporting of study findings. It is important to emphasize that in certain specialized clinical circumstances, even this training may not be sufficient for the independent performance of a TEE. For example, assessment of complex congenital heart lesions, and intraoperative evaluation of the suitability for and results of surgical repair of valvular regurgitation, are particularly demanding and require additional training and expertise.
Physicians who are not enrolled in a cardiology fellowship-training program need to acquire similar knowledge and to develop similar skills. This could be accomplished through an intensive period of training in an active TEE training program or through ongoing training under the guidance and supervision of an experienced (Level 3) echocardiographer with significant expertise in TEE.
Proof of competence (Table 9)
Documentation of competence can be achieved by means of a letter or certificate from the director of the echocardiography laboratory in which the trainee obtained TEE training or from the training program director, with input from the echocardiography laboratory director. This documentation should state that the trainee successfully achieved or surpassed each of the training elements, and the dates of training. For physicians whose training in echocardiography was completed before July 1, 1998, a Level 2 equivalence in TTE should be documented, as detailed in the previous section. In addition they must document performance of a minimum of 50 TEE cases per year, for the preceding two years. We believe that ideally, physicians should take the board examination offered by the NBE, and achieve certification in the relevant practice areas of echocardiography (i.e., general transthoracic, TEE, stress echocardiography, or comprehensive certification).
Maintenance of competence (Table 9)
Maintenance of competence in TEE requires both ongoing continuing education and regular performance of TEE examinations. Physicians performing TEE examinations should periodically attend postgraduate courses and workshops that focus on clinical applications of TEE, especially those that emphasize new and evolving techniques and developments. In addition, physicians should seek to compare the quality, completeness, and results of their own examinations with those presented at scientific meetings and in professional publications. On-line or other multimedia formats give physicians increasing access to a variety of materials that can help them keep up with the field.
Ongoing performance of diagnostic TEE examinations is needed to maintain technical skills and to keep up with developments in the field. Infrequent performance of TEE increases the risk of complications or of inaccurate results and inappropriate patient treatment. The guidelines on training in TEE published by the ASE in 1992 recommended performing 50 to 75 TEE examinations per year (8). Given the greater exposure to training in this modality over the past 10 years and recognizing that achieving such a volume may be difficult in routine clinical practice, this writing group recommends that a minimum of 25 to 50 cases per year be required to maintain adequate cognitive and technical skills in performing and interpreting TEE. Of course, TEE examinations should not be performed simply to meet these guidelines, but they must be indicated on clinical grounds and appropriate to good patient care. Physicians at the lower end of the recommended number should work in association with a laboratory where a greater volume is performed, so that they can be exposed to an adequate variety of pathology. On the other hand, physicians who cannot meet the recommended number should perform the procedure in conjunction with more experienced operators. Continuing medical education in echocardiography and TEE is essential to keep pace with ongoing technical advances, refinements in established techniques, and applications of new methods. Minimal CME requirements are outlined in Section A.
We also subscribe to the principles of Continuing Quality Improvement in Echocardiography (6), and recommend that a random sample of TEE studies performed by an individual operator periodically be reviewed by a qualified expert (from the operator’s own institution or, if necessary, from the outside), as part of a quality assessment program. This review should be performed in an educational and non-punitive manner and should help to determine if TEE studies had been performed for appropriate indications, if studies were of sufficient completeness and technical quality to resolve the relevant diagnostic questions, if findings were interpreted and reported correctly, and if results were reported in an effective and timely manner. Recurring variations from the norm would then serve to highlight areas for further quality improvement and thereby help facilitate better patient care. Continuing Quality Improvement considerations also mandate that the results of TEE examinations be compared, whenever possible, with the findings from cardiac catheterization or other cardiac imaging studies, cardiac surgery, or necropsy in order to establish and maintain diagnostic accuracy.
E. Perioperative echocardiography.
Overview and indications for the procedure
Perioperative echocardiography refers to the application of echocardiographic examination techniques in patients undergoing surgical procedures (intraoperative echocardiography) and during the early postoperative period. Early echocardiographic examinations used epicardial echocardiographic probes that had limited clinical applicability. Today, the examination is performed predominantly through the transesophageal approach, although epicardial and epivascular techniques continue to play a role during surgery, particularly in the echocardiographic assessment of the thoracic aorta.
Perioperative echocardiography utilizes most of the echocardiographic modalities used in the non-operative setting. They include M-mode and two-dimensional imaging techniques as well as pulsed, continuous-wave and color flow Doppler. Most modern transesophageal probes have multiplane capabilities. The ASE and the Society of Cardiovascular Anesthesiologists (SCA) have published guidelines for the performance of a comprehensive perioperative multiplane transesophageal examination (9).
The indications for perioperative echocardiography have been summarized by a task force of the American Society of Anesthesiologists/Society of Cardiovascular Anesthesiologists (ASA/SCA) and published as practice guidelines in 1996 (10). They can be divided into two broad categories: 1) indications that lie within the customary practice of anesthesiology, such as the perioperative diagnosis of myocardial ischemia and infarction, the perioperative assessment of hemodynamics and ventricular function, and the perioperative diagnosis and management of cardiovascular collapse; and 2) indications that guide surgical decisions in the operating room. In this regard, cardiovascular lesions are diagnosed, and the information is used to influence the patient’s surgical management. The results of surgical interventions may be assessed by echocardiography, and the findings may guide additional surgical therapy, if necessary. A physician should perform the perioperative echocardiographic examination. Although a sonographer may assist the physician, the physician must always be present to interpret the echocardiographic data and assist the surgeon in planning the surgical procedure.
Minimum knowledge required for performance and interpretation (Table 10)
Competence in performing and interpreting perioperative echocardiography in adult patients requires basic knowledge of ultrasound physics, instrumentation, and cardiac anatomy, physiology, and pathology outlined in the section on General Principles. Although several guidelines describe the knowledge necessary to perform echocardiography, few have focused on the specific knowledge and skills necessary for the practice of perioperative echocardiography. Specific guidelines on training in perioperative TEE have been recently published by an ASA/SCA Task Force (11). These recommendations which were developed mainly for anesthesiologists, recognized that perioperative echocardiography was practiced at different levels. Some anesthesiologists predominantly use echocardiography for monitoring purposes in the detection of myocardial ischemia or the evaluation of intracardiac hemodynamics and ventricular function (basic level), while others use the full diagnostic potential of echocardiography in the perioperative period (advanced level). The knowledge and skills necessary to practice perioperative echocardiography at the basic and advanced levels are summarized in Tables 10 and 11, respectively. For non-anesthesiologists who practice perioperative echocardiography, any necessary knowledge beyond what is listed in the tables relates to physiologic changes induced by anesthetic agents, mechanical ventilation, and cardiopulmonary bypass.
Training requirements (Table 12).
We endorse the recent ASA/SCA task force recommendation of two levels of training for perioperative echocardiography, basic and advanced (10,11). Both basic and advanced TEE training refer to specialized TEE training that extends beyond the minimum exposure to echocardiography that occurs during normal anesthesia residency training. Anesthesiologists with basic training are considered able to use TEE for indications that lie within the customary practice of anesthesiology. Anesthesiologists with advanced training are, in addition, able to utilize the full diagnostic potential of perioperative TEE.
The essential components of training include independent work, supervised activities, and assessment programs. Through a structured independent reading and study program, trainees must acquire an understanding of the principles of ultrasound and indications for perioperative echocardiography. This independent work should be supplemented by regularly scheduled didactics such as lectures and seminars designed to reinforce the most important aspects of perioperative echocardiography. Under appropriate supervision, trainees undergoing basic training learn to place the TEE probe, operate the ultrasound machine, and perform a TEE examination. Trainees should be encouraged to master the comprehensive examination defined by the ASE and SCA (9). A basic practitioner should be able to acquire all 20 of the recommended cross-sections, although not always needed for a basic examination, in the event they are needed for remote consultation with an advanced practitioner. For basic training, 150 complete examinations should be studied under appropriate supervision. These examinations must include the full spectrum of commonly encountered perioperative diagnoses and at least 50 comprehensive perioperative TEE examinations personally performed, interpreted, and reported by each trainee (Table 12).
For advanced practice, the comprehensiveness of training is paramount. The ASE/SCA Task Force (11) recommends that 300 complete examinations be studied under appropriate supervision. These examinations must include a wide spectrum of cardiac diagnoses and at least 150 comprehensive perioperative TEE examinations that are personally performed, interpreted, and reported by the trainee (Table 12). For both basic and advanced training, trainees must be taught how to convey and document the results of their examination effectively. Periodic formal and informal evaluations of trainees’ progress should be conducted during training. Trainees should keep a log of the examinations they performed and reviewed to document the depth and breadth of their training. The experience and case numbers acquired during basic training may be counted toward advanced training if the basic training was completed in an advanced training environment.
The ASE/SCA Task Force and this writing group recognize that trainees from different specialties will allocate their training schedules somewhat differently depending on their backgrounds. A cardiologist-echocardiographer with little operating room experience will need to spend more time in this environment to fully understand cardiac surgical techniques. A cardiac anesthesiologist or surgeon working in a center with a limited variety of cardiac surgery will need to spend more time in the echocardiographic laboratory to fully understand all of the diagnostic techniques in echocardiography.
Advanced training should take place after basic training in a training program designed specifically to accomplish comprehensive training in perioperative echocardiography. The director of the training program must be a physician with advanced training and proven expertise in perioperative echocardiography, who has performed at least 450 complete examinations, including 300 perioperative TEE examinations or equivalent experience. As advanced trainees acquire more experience, they may be allowed to work with more independence, but the immediate availability and direct involvement of an advanced practitioner is an essential component of advanced training. The supporting surgical program must have the volume and diversity to ensure that trainees will experience the wide spectrum of diagnostic challenges encountered in perioperative echocardiography and learn to use TEE effectively in all its established perioperative applications. The perioperative echocardiography training program should have an affiliation with an echocardiography laboratory so that trainees can gain regular and frequent exposure to teaching and clinical resources within that laboratory.
Proof of competence (Table 13)
Documentation of competence can be achieved by means of letters or certificates from the director of the perioperative echocardiography training program. This documentation should state the dates of training and that trainees have successfully achieved or surpassed each of the training elements.
Physicians already in practice can achieve appropriate training in perioperative echocardiography without enrolling in a formal training program. However, the same prerequisite medical knowledge, medical training, and goals for cognitive and technical skills apply to them as they apply to physicians in formal training programs. They should work with other physicians who have advanced TEE training or equivalent experience to achieve the same training goals and case numbers as the training levels previously delineated. It is the consensus of this writing group that physicians seeking basic training via this pathway should have at least 20 hours of CME devoted to echocardiography. Physicians seeking advanced training via this pathway should have at least 50 hours of CME devoted to echocardiography. The CME in echocardiography should be obtained during the time that trainees are acquiring the requisite clinical experience in TEE. Trainees should document their experience in detail and be able to demonstrate training equivalent in depth, diversity, and case numbers to the training levels previously delineated. Physicians who provide the training should document the successful completion of the training elements and the dates of training. We believe that, ideally, physicians should take the perioperative TEE board examination offered by the NBE and achieve certification in perioperative echocardiography.
Maintenance of competence (Table 13)
Clinical competence in perioperative echocardiography requires continued maintenance of skills in perioperative TEE including two-dimensional and Doppler examination. Upon completion of above training requirements, a minimum of performance and interpretation of 50 examinations per year is required to remain proficient in performing perioperative echocardiography. A program for continuous quality improvement in echocardiography should be employed as outlined in the ASE Continuous Quality Improvement document (6). Continuing medical education in perioperative TEE is essential to keep pace with ongoing technical advances, refinements in established techniques, and applications of new methods. Minimal CME requirements are outlined in Section A.
F. Stress echocardiography.
Overview and indications for procedure
Exercise electrocardiography is the standard noninvasive technique for the diagnosis of coronary artery disease. However, several situations (such as baseline ECG abnormalities and inability to exercise), reduce the sensitivity or specificity of exercise testing, or preclude its use entirely. In these situations, stress echocardiography is an important alternative.
There are two main modalities for performing stress echocardiography: 1) exercise stress echocardiography performed either during upright or supine bicycle exercise or immediately following treadmill exercise, and 2) pharmacologic stress echocardiography, most commonly performed using an intravenous infusion of dobutamine at a dose ranging from 5 mcg per kg per min to a maximum of 40 to 50 mcg per kg per min. Atropine is added at peak infusion dose if needed to achieve at least 85% of target heart rate. Side effects of dobutamine stress echocardiography include nausea, vomiting, headache, tremor, and anxiety. Serious complications such as myocardial infarction and death are very rare. Adenosine and dipyridamole can also be used as pharmacologic stressors. Atrial pacing using an esophageal lead or an implanted pacemaker is a third modality for performing stress echocardiography. Although it is not commonly used, this modality can provide an effective and safe method for inducing ischemia.
The normal cardiac response to stress is an increase in heart rate and myocardial contractility. Inducible myocardial ischemia is detected as failure to increase myocardial contractility or development of a new segmental wall motion abnormality. Indications for stress echocardiography include diagnosis of ischemic heart disease, evaluation of patients with known ischemic disease, and assessment of valvular heart disease.
Stress echocardiography can also be performed with spectral and color Doppler for the hemodynamic evaluation of patients with valvular heart disease. Ultrasonic contrast agents have been used to improve endocardial border detection. In the future, these agents might be used to evaluate myocardial perfusion.
Transesophageal dobutamine stress echocardiography has been used to improve endocardial visualization, but because of its invasive nature and the general improvement in transthoracic imaging with the use of contrast agents, this modality has not gained wide acceptance in clinical practice.
Minimum knowledge requirements for performance and interpretation (Table 14)
Competence in performing and/or interpreting stress echocardiograms in adult patients requires all of the basic knowledge of ultrasound physics, instrumentation, and cardiac anatomy, physiology and pathology described in the section on General Principles. In addition, the requirements for stress echocardiography contain two distinct components: 1) stress testing supervision; and 2) performance and interpretation of the echocardiographic images for wall motion analysis. Stress testing supervision requires the ability to safely monitor stress in an individual with potentially severe cardiovascular disease. A recent ACC/AHA Clinical Competence Statement on Stress Testing document by Rodgers et al. (12) addressed the cognitive skills, training requirements for establishing competence and requirements for maintaining competence in stress echocardiography. The document separates the skills needed to perform and supervise the stress portion of the test from those needed to perform and interpret the echocardiographic images. Recognition and treatment of life threatening arrhythmias is particularly relevant with dobutamine stress echocardiography. This writing group has decided to adopt the recommendations made by Rodgers et al. (12) which are summarized in this section.
Assessment of segmental wall motion remains one of the most challenging aspects of echocardiographic interpretation. Thus, intensive training in echocardiography with a minimum of Level 2 training or equivalent is a prerequisite for acquiring the skills necessary to perform and interpret stress echocardiography studies (13).
Training requirements (Table 15)
Specific recommendations for training in stress echocardiography have been published recently (12–14) and consist of achieving Level 2 training in echocardiography plus a minimum of 100 stress studies performed under the supervision of an echocardiographer with Level 3 training and expertise in stress echocardiography, including the independent interpretation of more than 200 stress echocardiograms, and maintenance of skills as outlined Table 16 (12).
Proof of competence (Table 16)
A letter from the program training director or training supervisor is expected to document the required training activity and competence. Physicians who intend to perform stress echocardiography and who completed training before the establishment of training levels are expected to achieve training equivalent to that acquired during formal fellowship. This should be achieved in a laboratory with sufficient volume to expose the physician to the same minimum of 100 stress echocardiograms, as previously outlined, under the direct supervision of an echocardiographer with Level 3 training and expertise in stress echocardiography.
Certification by the NBE is highly desirable. Certification requires successful completion of the Adult Special Competence Examination in Echocardiography as well as documentation of training and maintenance of skills. For individuals completing training after 1998, a letter from the training director or section head documenting Level 2 training and performance/interpretation of 100 or more stress echocardiograms is required. For physicians completing cardiovascular training before 1998, a letter documenting performance and interpretation of 400 or more transthoracic echocardiograms and 100 or more stress echocardiograms during each of the two preceding years is required. This letter should be obtained from the laboratory medical director or the hospital chief of staff.
Maintenance of competence (Table 16)
The accurate assessment of regional wall motion during stress is difficult enough to require continuous exposure to an adequate mix of normal and abnormal cases in order to maintain competence. The ASE document recommended a volume of 15 stress echoes per month to remain competent (14). However, it was the consensus of the experts writing the ACC/AHA Competence Statement on Stress Testing that an individual with established skills could maintain competence with a volume of 100 studies per year (12). We endorse this recommendation. Physicians with a lesser volume should perform and/or interpret stress echoes in association with an experienced echocardiographer who achieves the recommended volume of studies in his or her practice. Continuing medical education in stress echocardiography is essential to keep pace with ongoing technical advances, refinements in established techniques, and applications of new methods. Minimal CME requirements are outlined in Section A. A program for continuous quality improvement in stress echocardiography should be employed, as outlined in the ASE Continuous Quality Improvement document (6).
G. Echocardiography for CHD patients.
Overview and indications for procedure
Echocardiography is an important resource used in the evaluation of infants, children, and adults with suspected or documented CHD. It has been widely applied for the last several decades and has become a mainstay in daily clinical use. As applied to infants, children, and adults with CHD, echocardiography is comprised of all of the previously described modalities. When combined, they provide a comprehensive anatomic diagnosis along with the assessment of associated flow disturbances. Such information is obtained noninvasively, without patient risk or discomfort. The high accuracy of the information is often sufficient to preclude the need for further invasive diagnostic studies such as cardiac catheterization. Numerous echocardiographic methods have been developed with high sensitivity and specificity for individualized diagnosis and assessment of disease severity. In addition to the method’s high accuracy, it has prime utility in serial evaluation of patients for surveillance of the severity and progression of the disease, and the response to therapy.
Echocardiography is indicated in the evaluation of the cardiac anatomy and physiology of infants and children in whom cardiac concerns are present, and in adults with known or suspected CHD. This includes patients in whom cardiac malformations are suspected because a heart murmur has been detected or because of concerns about cyanosis, or congestive failure, or abnormal findings on chest X-ray or ECG. The frequency of repeat echocardiographic examination depends on the severity of the disease, the type of intervention performed, and the age of the patient. Whether it is performed in infants, children, or adults, echocardiography of patients with CHD requires a special knowledge base that is usually acquired during a fellowship in pediatric cardiology. In most cases, a properly trained adult cardiologist with Level 2 or 3 competence in echocardiography should be capable of recognizing simple congenital heart defects (Table 3) and treating affected patients appropriately. However, the same does not apply to complex lesions. Few adult cardiology training programs have a sufficient caseload and case mix of complex lesions to ensure an adequate level of training. Although adult cardiologist echocardiographers may often recognize the presence of a complex CHD, the comprehensive evaluation and management of these lesions require special skills not usually acquired during a conventional adult cardiology fellowship. With the growing number of adults with complex CHD, there is an acknowledged need for cardiologists trained specifically in the care of these patients (15). Practitioners in adult CHD require special expertise in echocardiography similar to that possessed by pediatric echocardiographers. This section describes the skills required for performing echocardiography in pediatric patients and in adults with complex CHD, along with the training requirements and criteria for proof of competence and maintenance of competence in this area. The definition of "complex CHD" is any congenital lesion other than those mentioned in Table 3.
Minimum knowledge required for performance and interpretation (Table 17)
Competence in performing and/or interpreting echocardiograms in pediatric patients and in adults with complex CHD requires all of the basic knowledge of ultrasound physics, of instrumentation, and of cardiac anatomy, physiology, and pathology described in the section on General Principles. In addition, a pediatric echocardiographer must be skilled in observing and understanding the behavioral and developmental aspects of infants and children of all ages, in order to alleviate patient fear, establish patient confidence, and be persuasive enough to allow the proper completion of a cardiac ultrasound examination. At times, echocardiographers may be required to administer sedation to obtain adequate examinations, and knowledge of these agents is necessary. These skills are specific to those practitioners performing examinations in children and do not apply to individuals performing examinations only in adults with CHD.
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Table 17 Cognitive Skills Required for Performance and Interpretation of Echocardiography in Patients With Complex CHD
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Technical aspects of the examination
An echocardiographer must be personally skilled in all aspects of the technical performance and recording of the examination. This includes a review of the indications and goals of the study and the formulation of a plan to accomplish those goals. One must know how to use ultrasound probes of different frequencies to obtain the most comprehensive information possible in a given patient, particularly infants and premature babies. An echocardiographer must be able to scan from all available echo windows and integrate the information from each view. In addition, he/she must be familiar with the use of ultrasound contrast agents, which can enhance the detection of intracardiac shunts. These skills are required even when a physician has access to a sonographer for performance of the examination. Supervising physicians cannot supervise adequately unless they themselves, are capable of performing echocardiograms on infants and children.
Anatomy and physiology
An echocardiographer examining a patient with complex CHD must be skilled in recognizing anatomic features that identify and characterize specific cardiac structures and allow for diagnosis of specific cardiac malformations. Echocardiographers must be able to identify the abdominal and thoracic situs and perform an anatomic assessment in a segmental anatomic sequence that identifies not only anatomy but also connections. He or she must be fully familiar with associated disease processes and their effect on anatomic findings.
The physiology of many congenital lesions and combinations of lesions is interrelated. The echocardiographer must be familiar with the influence of age, patient size, and hemodynamic state in each lesion, and they must understand the transitional physiology of the neonate, shunt physiology, and the concepts and manifestations of pulmonary hypertension throughout the full pediatric and adult-age spectrum. The echocardiographer must be familiar with established techniques used to quantify cardiac function and evaluate different physiologic states and must know how to evaluate the consistency (or lack thereof) of results obtained with these techniques in a given patient.
Recognition of simple and complex pathology
An echocardiographer must have sufficient knowledge and experience to be aware of defects or problems that may cluster together. He/she must be aware of cardiac defects associated with various syndromes and be able to recognize the dysmorphic features of those syndromes.
An echocardiographer must know how to evaluate the several anatomic and physiologic abnormalities that coexist in patients with complex malformations and recognize the effects of altered physiology. They will commonly encounter patients who have undergone surgical intervention for a variety of cardiac problems and for each, they must be aware of the type of surgical procedure and its specific echocardiographic findings. For some lesions, surgical techniques have evo |
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