Clarification: "Echocardiogram" and "Transthoracic Echo" Are the Same Test
You do not need both an echocardiogram and a transthoracic echo (TTE) because they are the exact same examination. The term "echocardiogram" is simply the general name for cardiac ultrasound, and "transthoracic echocardiography (TTE)" specifies the approach—imaging through the chest wall 1. This is the standard, first-line cardiac ultrasound examination performed in adults 1.
Understanding the Terminology
- Transthoracic echocardiography (TTE) is the complete technical term for what clinicians commonly call an "echocardiogram" 1
- TTE involves placing an ultrasound probe on the chest wall to visualize cardiac structures through standard acoustic windows 2
- This is a non-invasive, widely available, safe, and painless examination that provides real-time 2D imaging with Doppler assessment of blood flow 1
When Additional Imaging Beyond Standard TTE Is Actually Needed
The confusion likely stems from situations where TTE alone is insufficient, requiring transesophageal echocardiography (TEE)—a different examination entirely 1.
Indications for TEE After TTE:
- Prosthetic valve evaluation: TTE has only 50% sensitivity for prosthetic valve endocarditis, while TEE achieves 90% sensitivity 3
- Suspected endocarditis with high clinical suspicion: TEE should be performed when TTE is negative but clinical suspicion remains high, as TEE has 85-90% sensitivity versus 75% for TTE 1, 3
- Poor acoustic windows: Patients with chronic obstructive lung disease, previous cardiac surgery, morbid obesity, or severe emphysema may have non-diagnostic TTE images 1
- Perivalvular complications: TEE is superior for detecting abscesses, pseudoaneurysms, and fistulas 1, 3
- Great vessel imaging: TTE has difficulty visualizing the ascending aorta, pulmonary arteries, and systemic/pulmonary venous connections in adults 1
- Atrial structures: TEE provides superior visualization of atrial appendages, atrial septum, and atrial baffle function 1
The Complementary Relationship:
- TTE and TEE are mutually complementary examinations, not duplicative 4
- The American Heart Association recommends performing TTE first in all suspected endocarditis cases, then proceeding to TEE based on clinical risk and TTE findings 1
- TEE is invasive, requires pharyngeal anesthesia and intravenous sedation, and carries a 3-5% failure rate due to patient intolerance 1
Clinical Algorithm for Echocardiographic Evaluation
Initial Assessment:
- Perform TTE as the first-line imaging study for all cardiovascular evaluations including heart failure, valvular disease, congenital heart disease, and suspected endocarditis 1
Proceed to TEE When:
- TTE is technically limited or non-diagnostic 1, 4
- High-risk features are present: prosthetic valves, previous endocarditis, new atrioventricular block, or persistent fever despite negative TTE 1
- Surgical planning requires detailed perivalvular anatomy 1
Common Pitfall to Avoid:
Do not order "both an echocardiogram and a TTE"—this represents ordering the same test twice under different names 1. Instead, clarify whether the clinical question requires standard TTE alone or whether TEE is indicated based on the specific diagnostic needs outlined above 1, 4.