Contrast Echocardiography for Detecting Cardiac Shunts

Purpose and Clinical Applications

The American College of Cardiology considers bubble studies essential for detecting right-to-left shunts, which is a standard requirement for echocardiography training 2
Bubble studies help identify potential causes of cryptogenic stroke, where patent foramen ovale (PFO) may lead to paradoxical embolism, particularly in patients with suspected congenital heart defects 1
The European Heart Journal recommends using commercial ultrasound contrast agents (microbubbles) during stress echocardiography to improve diagnostic accuracy 3
Bubble studies are crucial for evaluating patients with suspected congenital heart defects by verifying the presence of shunts, and for diagnosing pulmonary arteriovenous malformations (PAVMs) in patients with hereditary hemorrhagic telangiectasia, with transthoracic echocardiography with contrast showing 98-99% sensitivity for detecting PAVMs 1
The American College of Cardiology recommends level III training in contrast echocardiography, which should include instruction on the chemical composition and physical properties of ultrasound enhancing agents, advanced ultrasound equipment settings, safety issues, and protocols 2

Bubble studies can be performed during both transthoracic (TTE) and transesophageal (TEE) echocardiography, with TEE providing higher sensitivity (51% vs. 32%) for detecting shunts compared to TTE 1
The European Heart Journal recommends using intravenous ultrasound contrast agents during stress echocardiography when two or more contiguous myocardial segments are not visualized to improve diagnostic accuracy 3
Myocardial perfusion using contrast agents during stress echocardiography is recommended to improve diagnostic accuracy and refine risk stratification beyond wall motion 3