AIM   To explore the application value of contrast transthoracic echocardiography (c-TTE) in screening patent foramen ovale with right to left shunt (PFO-RLS).

  METHODS  A total of 103 patients with suspected PFO due to migraine or unexplained cerebral infarction in the Neurology Department of our hospital underwent c-TTE and contrast transesophageal echocardiography (c-TEE) examinations to observe the positive rate of PFO-RLS detected by c-TTE and c-TEE at rest and under Valsalva maneuver. The results of c-TEE were regarded as the “gold standard” for PFO-RLS diagnosis and the diagnostic efficiency of c-TTE was evaluated under Valsalva maneuver.

  RESULTS  The positive rates of c-tte and c-tee were 38.83% and 40.78% respectively at rest. The positive rates of the two methods were significantly higher under Valsalva action (all P<0.05), 80.58% and 82.52% respectively. There was no significant difference between the positive rates of c-tte and c-tee between the two groups at rest and Valsalva action; Compared with the gold standard c-tee, the positive predictive value of resting c-tte for pfo-rls was 100%, the negative predictive value was 96.82%, the sensitivity was 95.23%, the specificity was 100%, the accuracy was 98.05%, and the consistency kappa value was 0.95. Under Valsalva action, the positive predictive value of c-tte for pfo-rls was 98.79%, the negative predictive value was 85.00%, the sensitivity was 96.47%, the specificity was 94.44%, the accuracy was 96.11%, and the consistency kappa value was 0.87.

  CONCLUSION  c-TTE has high sensitivity, specificity and accuracy in the diagnosis of PFO-RLS patients. As c-TTE is minimally invasive, painless, convenient and easy to be popularized in clinical application, it can be used as an early screening method for PFO-RLS patients. c-TEE should be performed for accurate assessment of PFO morphologies when the closure is planned.