Echocardiographic diagnosis of right-to-left shunt using transoesophageal and transthoracic echocardiography

Mirae Lee, Ju Hyeon Oh
Open Heart 2020, 7 (2)

BACKGROUND: The diagnosis and quantification of right-to-left shunt (RLS) using transthoracic echocardiography (TTE) as well as transoesophageal echocardiography (TOE) have not been well established. We aimed to diagnose RLS by TOE using direct visualisation of the shunt and to compare the diagnosis with TTE diagnosis using conventional methods.

METHODS AND RESULTS: We evaluated 141 patients with ischaemic stroke for RLS by both non-sedation TOE and TTE using saline contrast and Valsalva manoeuvre. The amount (graded as 0 to IV) and timing of RLS were demonstrated. All patients were classified into four groups by TOE based on direct visualisation of shunt through a patent foramen ovale (PFO) or either pulmonary vein: no shunt (group 1: n=11), PFO (group 2: n=47), pulmonary RLS (group 3: n=25) and indeterminate RLS (group 4: n=58). All cases in group 3 showed delayed shunt, and all cases in group 4 had small shunt. On TTE findings, all cases with early appearing large shunt (cardiac cycles ≤3 and shunt grade ≥III) were group 2. Six of the eight patients with delayed appearing large shunt on TTE were group 3. TTE diagnosis of PFO using criteria of cardiac beats ≤3 and grade ≥II had a sensitivity of 85% and a specificity of 98% compared with TOE diagnosis using shunt visualisation.

CONCLUSIONS: Compared with TOE using shunt visualisation, TTE accurately diagnosed large PFO using criteria of cardiac cycles ≤3 and shunt grade ≥III. TTE possibly diagnosed pulmonary shunt using criteria of cardiac cycles >3 and shunt grade ≥III. Both modalities showed limitations in diagnosing small amount of RLS.

Full Text Links

Find Full Text Links for this Article


You are not logged in. Sign Up or Log In to join the discussion.

Related Papers

Remove bar
Read by QxMD icon Read

Save your favorite articles in one place with a free QxMD account.


Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"