Transthoracic echocardiography using second harmonic imaging with Valsalva manoeuvre for the detection of right to left shunts

Eur J Echocardiogr. 2004 Jun;5(3):176-81. doi: 10.1016/S1525-2167(03)00076-3.


Aims: To assess transthoracic echocardiography (TTE) using second harmonic imaging with Valsalva manoeuvre compared to transesophageal echocardiography (TEE) for the diagnosis of right to left cardiac and pulmonary shunts.

Methods and results: One hundred and ten patients referred for TEE underwent TTE with bubble contrast. Bubbles in the left atrium within three cardiac cycles were considered diagnostic for a patent foramen ovale (PFO) and later as a pulmonary shunt. Greater than 20 bubbles in the left atrium was considered a large shunt and less than 20 a small shunt. TEE was performed immediately afterwards and read blinded to the TTE results. Pick-up rates were similar with 19 TEE positive (13 PFO) and 18 TTE positive (14 PFO) patients. There were five TEE positive/TTE negative cases who had significantly poorer TTE image quality score (2.7 +/- 0.8 vs 1.9 +/- 0.6, p < 0.05). There were six TEE negative/TTE positive cases, two cases requiring Valsalva manoeuvre to become positive. The Valsalva manoeuvre significantly increased the number of bubbles shunting (10 +/- 11 vs 20 +/- 19, p < 0.005).

Conclusion: TTE with Valsalva manoeuvre is as good as TEE in diagnosing shunts. Valsalva manoeuvre increases the size of shunt. Both techniques produce false negative results.

Publication types

  • Comparative Study

MeSH terms

  • Aged
  • Cardiac Output / physiology
  • Coronary Circulation / physiology
  • Coronary Thrombosis / diagnostic imaging
  • Echocardiography / methods*
  • Embolism, Paradoxical / diagnosis
  • Embolism, Paradoxical / diagnostic imaging*
  • Female
  • Heart Septal Defects, Atrial / diagnosis
  • Heart Septal Defects, Atrial / diagnostic imaging*
  • Humans
  • Male
  • Middle Aged
  • Pulmonary Embolism / diagnostic imaging
  • Sodium Chloride
  • Valsalva Maneuver*


  • Sodium Chloride