Agitated Saline Contrast Echocardiography in the diagnosis of right to left shunts: Guidance and recommendations from the British Society of Echocardiography

Contrast echocardiography encompasses two forms of ultrasound contrast agents. This article focuses on agitated saline (AS-C) contrast, commonly called ‘bubble’ contrast. Its main application is in identifying the presence of a right to left shunt in a number of clinical syndromes, often associated with a patent foramen ovale (PFO). Dependant on the clinical presentation, the presence of a PFO with a likelihood of a causal role may be considered for percutaneous PFO closure. This guideline outlines a structured approach to performing an AS-C transthoracic echocardiogram, including the indications, protocols, and potential pitfalls for performing AS-C transthoracic echocardiography (TTE). It also addresses when to proceed to more advanced imaging modalities and highlights clinical decision-making frameworks such as the RoPE score.