From the Guidelines
A bubble echocardiogram, also known as a saline contrast echocardiography or "bubble echo," is a diagnostic test that uses tiny air bubbles to enhance the visualization of heart structures and blood flow. This test is particularly useful for verifying the presence of a shunt and differentiating intracardiac from extracardiac shunts, as noted in the study by 1.
Key Points About Bubble Echocardiogram
- The procedure involves injecting a sterile saline solution containing microscopic air bubbles into a vein, which then travel to the heart and reflect ultrasound waves, creating a clearer picture of blood flow patterns 1.
- The test is useful for detecting holes between heart chambers, evaluating heart valve function, assessing blood flow through the heart, and examining the heart muscle in patients with poor image quality on standard echocardiograms.
- The procedure typically takes 30-60 minutes and is generally painless except for minor discomfort from the IV insertion, with minimal risks associated with the contrast agent used 1.
- The contrast agent is generally safe and is eliminated from the body naturally within minutes after the test.
Clinical Utility and Limitations
The bubble echocardiogram is a valuable tool in the investigation of congenital heart disease (CHD) in adults, as it provides a unique 2-D, real-time evaluation of the anatomic and hemodynamic relationships of intracardiac lesions 1. However, it may have limitations in certain adult patients with intracardiac defects, particularly those with poor acoustical windows, where transesophageal echocardiography (TEE) and MRI may be more useful 1.
Recommendation
Based on the most recent and highest quality evidence, a bubble echocardiogram is recommended for patients with suspected CHD or those who require evaluation of heart structures and blood flow, particularly when standard echocardiograms are inconclusive 1.
From the Research
Definition of Bubble Echocardiogram
A bubble echocardiogram, also known as contrast echocardiography, is a type of ultrasound-based procedure that uses acoustic enhancing agents, usually microbubbles, to improve diagnostic performance 2.
Purpose of Bubble Echocardiogram
The purpose of a bubble echocardiogram is to:
- Improve the visualization of the heart and its structures
- Detect right-to-left shunt (RLS) due to patent foramen ovale (PFO) 3, 4
- Evaluate the severity of PFO-RLS 5
- Diagnose other cardiac conditions, such as myocardial perfusion defects 2
Procedure of Bubble Echocardiogram
The procedure of a bubble echocardiogram typically involves:
- Administering a contrast agent, such as agitated saline or vitamin B6 and sodium bicarbonate, through an intravenous route 3, 5
- Performing a transthoracic echocardiography (TTE) or transesophageal echocardiography (TEE) to visualize the heart and detect the presence of microbubbles in the left heart 3, 4
- Using the Valsalva maneuver or cough to increase the sensitivity of the test 3, 6
Diagnostic Value of Bubble Echocardiogram
The diagnostic value of a bubble echocardiogram is:
- High sensitivity and specificity for detecting PFO-RLS 5
- Ability to predict PFO size and severity of RLS 6
- Useful for diagnosing other cardiac conditions, such as myocardial perfusion defects 2
Key Findings
Key findings of bubble echocardiogram studies include: