Diagnostic Echocardiography Laboratory: Structure, Standards, and Quality Improvement

Laboratory Structure

The laboratory structure can be divided into a minimum of four components: the physical laboratory, equipment, personnel (sonographers and physicians), and the imaging and reporting process ( Table 7.1 ). For each of these components, standards have been defined. For the physical laboratory, accreditation by the IAC is recommended for existing laboratories; new facilities should initiate the process for submitting applications within 2 years after beginning operation.

Laboratory Accreditation

The IAC is an independent, not-for-profit organization formed in the 1990s by a consortium of medical subspecialty stakeholder societies that recognized that patient care would benefit from an organization whose sole mission was laboratory accreditation. In 1996, the IAC’s sponsoring organizations commissioned the Intersocietal Commission for the Accreditation of Echocardiography Laboratories (ICAEL). The ICAEL name was retired in 2006 after all the IAC’s divisions merged, and the commission’s echocardiography division was renamed IAC Echocardiography. This division now accredits laboratories performing adult transthoracic, adult transesophageal, adult stress, pediatric transthoracic, pediatric transesophageal, fetal, and (in the near future) perioperative transesophageal echocardiography. The IAC’s accreditation model is centered on laboratory standards that were written by the IAC Echocardiography’s board of directors (content knowledge experts) and accepted after a public comment period. Standards are derived from the appropriate peer-reviewed clinical practice guidelines and consensus documents, including AUC.

IAC Echocardiography’s laboratory standards are publicly available on the organization’s website. The IAC accreditation process includes an objective quality review of a laboratory’s submitted actual work (complete images and reports) and laboratory protocols and verification that the ongoing internal QI practices are such that any deficiencies become self-correcting within a laboratory. The IAC’s minimum-standards format can be used by very small laboratories with limited goals or as an invaluable foundation on which more complex laboratories can build as needed. The standards are updated approximately every 2 years or when dictated by major changes in the field.

The IAC Adult Echocardiography Standards are divided into the following domains:

• Personnel and supervision (medical staff, technical staff, support services)

• Facility (examination and interpretation areas, storage, instrument maintenance)

• Examination reports and records

• Facility safety

• Quality Improvement program

Physician Training

Physicians who interpret echocardiograms are required to have considerable training and expertise. The Accreditation Council for Graduate Medical Education (ACGME) provides regulatory oversight for internal medicine subspecialty training programs. The American Board of Internal Medicine (ABIM) certifies individual specialists and subspecialists. The American College of Cardiology (ACC) has aligned with the ACGME and ABIM to provide curricular content detailed by the Core Cardiology Training Symposium (COCATS) documents for proficiency and competency (levels I, II, and III) in the various cardiovascular disciplines, including adult echocardiography.

Unlike prior COCATS documents, the 2015 COCATS 4 training statement focuses on level I and level II echocardiography training and addresses competency and outcomes-based training, as opposed to focusing solely on time spent in a laboratory and on procedural volumes. Level I training covers transthoracic echocardiography (TTE) only; it is required for all cardiology fellows and is a prerequisite for level II training. Level II includes TTE, contrast, TEE, and stress echocardiography; it is the minimal requirement for independently performing and interpreting echocardiograms. This level of competency can be achieved in many standard 3-year cardiology fellowship programs, depending on the trainee’s career interests and the use of available elective time.

Level III echocardiography training was the focus of the 2019 Advanced Training Statement on Echocardiography published by the ACC, the American Heart Association (ASA), and the American Society of Echocardiographers (ASE). It consists of training beyond level II that includes

• acquiring additional expertise in advanced imaging techniques (3D, strain, contrast, stress echocardiography for structural heart disease);

• treating specialized populations (adult patients with congenital conditions, advanced heart failure, or complex valve disease), mechanical circulatory support device evaluation, and cardio-oncology;

• performing TTE and TEE during cardiovascular interventions (pericardiocentesis, endomyocardial biopsy, structural heart interventions);

• adequate exposure to emergency echocardiography; and

• data analysis and reporting.

Level III training should occur in an accredited laboratory so that trainees can understand the importance of laboratory structure, including the implementation and maintenance of QI processes.

Whether a laboratory intends to operate as an ACGME-accredited training facility has implications with regard to laboratory structure as defined by the COCATS 4, Task Force 5 statement. The IAC does not provide a separate, more advanced accreditation standard for teaching laboratories aspiring to provide advanced (level III) ACGME-approved physician training or for laboratories that could be described as providing comprehensive echocardiography services, although training laboratories should be IAC-accredited. Advanced and teaching laboratory leaders should review the facility and staff training recommendations provided in the recent COCATS 4, Task Force 5 statement and the ACC/AHA/ASE Advanced Training Statement on Echocardiography because a variety of additional resources (beyond minimal laboratory accreditation standards) must be available, including level III-trained mentors, an environment of scholarship and learning, and teaching sonographers with both the time and the ability to provide hands-on instruction in scanning and image-optimization techniques as specified in Table 7.2 for each physician trainee.

Medical Director

The medical director of an IAC-accredited laboratory is a licensed physician who ensures that both medical and technical staff members comply with the laboratory’s standards. The medical director must actively participate in interpretation of studies performed in the laboratory. Although the medical director may delegate supervision of specific laboratory operations, he or she is ultimately responsible for all clinical services provided by the laboratory, including determining examination appropriateness and quality. For recent trainees with level II or level III initial training and National Board of Echocardiography (NBE) Testamur status, assuming the medical directorship must be preceded by at least 18 months of qualifying echocardiography practice experience; trainees without NBE Testamur status must have qualifying clinical practice experience over the preceding 24 months, as outlined in the standards. The medical director standards are designed to accommodate physicians who completed their initial training in years past and have no level II or level III training documentation but who have maintained an ongoing robust clinical echocardiography practice experience (≥1800 examinations) and qualifying practice experience over the previous 36 months. Medical directors must have completed a program of at least 30 hours of echocardiography-relevant continuing medical education (CME) activity over the preceding 3 years. This CME requirement is considered fulfilled when a physician obtains the NBE Testamur certificate or when a physician’s initial echocardiography COCATS level II or level III training has been completed within 3 years of joining the laboratory.

Medical Staff

Members of the medical staff must also be licensed physicians who meet at least one of three criteria: (1) documented initial level II or III COCATS training, (2) unable to provide evidence of initial level II or III training but with active NBE Testamur status and qualifying clinical practice experience over the preceding 12 months, and (3) cumulative practice experience of at least 600 echocardiography examination interpretations and qualifying practice experience over the preceding 12 months. All medical staff members must perform and/or interpret at least 150 TTE examinations, 25 TEE examinations, and 25 stress echocardiography examinations per year (on average over 3 years), and these need not all be performed in the same IAC-accredited laboratory. All regular medical staff members must participate in the laboratory’s QI program and obtain at least 15 hours of echocardiography-related CME over a 3-year period.

Technical Director

Technical director is a full-time, on-site position, although provisions can be made for supervision of additional sites when a credentialed technical staff member is available to perform the technical director’s duties at each site. Laboratory technical directors must have an active credential issued by one of the organizations listed in Table 7.3 .

The technical director is responsible for overseeing day-to-day laboratory operations—including equipment inventory and maintenance and compliance with the standardized scanning protocols—and ensuring the proper function of the laboratory’s ordering, imaging, online and offline analysis, reporting, and data archival infrastructure. The technical director and medical director, as a team, ensure that the medical and technical human resources are appropriate for the laboratory’s intended scope of practice. The technical director works closely with the appropriate facility administrator and ancillary nursing staff to support patients’ experience, safety, and confidentiality and to ensure compliance with local, state, and federal regulations. Other laboratory organizational duties include coordinating information technology (IT) and biomedical support teams and implementing and maintaining the laboratory’s QI program.

A technical director should allocate time for actively participating in the laboratory’s daily clinical work to spot problem areas and to serve as a role model, “second pair of hands,” and an educational resource for junior sonographers and other trainees. The diagrams in Figs. 7.2, 7.3, and 7.4 can be modified as appropriate to illustrate a given technical director’s purview. Dedicated administrative time may vary with the facility’s size, complexity, and supporting resources. The newly available Advanced Cardiac Sonographer (ACS) credential (see Table 7.3 ), although not required, has enabled sonographers to demonstrate their experience and mastery of the exceptional skills needed in an advanced or comprehensive teaching echocardiography laboratory.

Technical Staff

All accredited laboratory technical staff members must have one of the credentials listed in Table 7.3 . Prerequisites for taking a credentialing examination typically include graduation from a Council on Accreditation of Allied Health Education Programs (CAAHEP)-accredited ultrasonography training school. When a laboratory employs new ultrasonography program graduates who are not yet credentialed, these employees must be listed in the laboratory’s IAC accreditation application as “provisional” technical staff members with a plan to pass their credentialing examination within 1 year of their graduation date. Individuals employed in an accredited facility who are cross-training to fulfill the clinical experience prerequisites required for eventual adult echocardiography certification (to be obtained within 2 years) are also listed as provisional technical staff members. Provisional technical staff members must operate under the supervision of appropriately credentialed sonographers. All technical staff members, including the technical director, must earn 15 hours of echocardiography-related CME credits over 3 years; this requirement is automatically fulfilled when sonographers remain in good standing with their credentialing organization.

Ancillary Personnel

Laboratories require enough clerical and administrative support staff members to ensure efficient operation and record keeping. Nursing and other ancillary clinical support personnel (e.g., medical assistants, exercise physiologists) working under the supervision of medical staff should be formal members of the echocardiography team (see Fig. 7.2 ) with clearly defined roles and availability, particularly if they are working in shared arrangements with other departments and not as full-time laboratory employees. Levels of supportive care vary according to a laboratory’s scope of practice but may include placing and managing peripheral intravenous (IV) access, administering IV saline contrast or ultrasound enhancing agents, managing conscious sedation protocols (for TEE) and pharmacologic and exercise testing protocols (for stress echocardiography), and ensuring the appropriate level of ongoing care (e.g., oxygen delivery, telemetry monitoring, continuous IV drug delivery) for patients transported to the echocardiography laboratory. The laboratory should follow appropriate facility transportation, monitoring, and handoff procedures.

Some laboratories have formal relationships with nurse anesthetists or anesthesiologists for delivering moderate or higher levels of sedation for TEE procedures. Stress echocardiography testing protocols should be managed by appropriately trained individuals (e.g., exercise physiologists, nurses, physicians). If patients with mechanical circulatory support devices are studied, the appropriate care team, a supervising knowledgeable echocardiography medical staff member, or both should be present when device-setting changes are made by the heart failure team or by circulatory support technical staff members under their supervision.