What an echocardiographer images, the exams they perform, the conditions those exams find, and the credentials and settings that define the specialty.
Cardiac sonography is the imaging of the heart with sound. A cardiac sonographer — often called an echocardiographer — produces moving pictures of the heart’s chambers, valves, and muscle, and uses Doppler to measure blood flow through it. The test is called an echocardiogram, or “echo.” It is one of the most common cardiology tests, and it is its own specialty with its own credential, separate from general sonography.
What it images
An echocardiogram looks at the heart’s main structures: the four chambers (the left and right atria and ventricles), the four valves (mitral, aortic, tricuspid, and pulmonic), the myocardium (the heart muscle, or walls), the pericardium (the sac around the heart), and the start of the great vessels — the proximal aorta and pulmonary artery (American Society of Echocardiography, 2024–2025). The exam assesses chamber size, how the walls move, how the valves open and close, and how blood flows across them.
The central number an echo produces is the left ventricular ejection fraction (LVEF) — the share of blood the heart’s main pumping chamber ejects with each beat. It is the standard index of the heart’s pumping strength, and the transthoracic echocardiogram is the standard way to measure it (ASE, 2025).
The common studies
- Transthoracic echocardiogram (TTE). The standard, non-invasive exam, performed by moving the transducer across the outside of the chest. This is the workhorse study and the bulk of most cardiac sonographers’ work (ASE, 2025).
- Transesophageal echocardiogram (TEE). A small probe is passed into the esophagus for clearer views of the back of the heart. A physician usually drives the probe; the sonographer assists.
- Stress echocardiography. Images taken before and after exercise or medication that stresses the heart, used to look for reduced blood flow when resting images are normal but symptoms persist (ASE, 2022).
- Doppler and strain imaging. Spectral, color, and tissue Doppler measure blood-flow speed and direction; strain imaging measures how the heart muscle deforms, giving an early read on function (ASE, 2024–2025).
The conditions it helps find
Echocardiography is central to diagnosing valvular heart disease — narrowing (stenosis) or leaking (regurgitation) of the valves, graded from mild to severe. It also evaluates cardiomyopathy (disease of the heart muscle), heart failure with reduced or preserved ejection fraction, wall-motion problems from poor blood supply, pericardial effusion (fluid around the heart), congenital structural defects, infection on the valves (endocarditis), and clots inside the heart (ASE guidelines, 2019–2025).
The credentials
Cardiac imaging can be credentialed through either of two bodies, and they are different exams:
- RDCS — Registered Diagnostic Cardiac Sonographer, issued by the American Registry for Diagnostic Medical Sonography (ARDMS), with an Adult Echocardiography specialty. The ARDMS path requires the Sonography Principles and Instrumentation (SPI) physics exam plus the adult echo exam, within five years (ARDMS, 2024).
- RCS — Registered Cardiac Sonographer, issued by Cardiovascular Credentialing International (CCI). Its current pathways took effect July 1, 2023; the RCS235 route, for example, requires a health-science academic program, one year of full-time cardiac ultrasound experience, and at least 600 cardiac ultrasound studies (CCI, 2023).
Neither is “the” cardiac credential — they are parallel routes covering much the same scope. Licensing and Certification compares the credentialing bodies.
Where the work happens
Cardiac sonographers work in hospital cardiology and cardiac-imaging departments, outpatient cardiology clinics, and dedicated echocardiography labs. Many echo labs are accredited by the Intersocietal Accreditation Commission (IAC); IAC-accredited echo facilities require their technical staff to hold a cardiac credential such as the RDCS or RCS, and new graduates must earn one within a year of graduation (IAC Adult Echocardiography Standards, 2025).
A note on pay and outlook
This is the one specialty the U.S. Bureau of Labor Statistics counts separately. Echocardiographers fall under “cardiovascular technologists and technicians” (occupation code 29-2031), not under “diagnostic medical sonographers” (29-2032). The commonly cited sonographer wage and growth figures describe 29-2032 and do not represent cardiac echo. A cardiac-specific figure has to come from the 29-2031 data. Sonography Specialties explains the split.
Last verified: 2026-06-14. Credential pathways and exam requirements change; confirm current details with ARDMS and CCI. This page is informational and does not recommend a specialty or credential.