Detection of a persistent foramen ovale using echocardiography.

Right-to-left shunts can result in decompression illness in divers and lead to a number of other conditions. Transthoracic echocardiography with intravenous injection of bubble contrast, when performed according to a well-tested protocol by trained personnel, enables the safe, simple, rapid and inexpensive detection of right-to-left shunts, the assessment of the size of the shunts and the differentiation of atrial shunts from pulmonary shunts. This article summarises the author's views on the techniques available and his preferred protocol for transthoracic echocardiography.