Correlation of the flow patterns among the four pulmonary veins as assessed by transesophageal echocardiography: Influence of significant mitral regurgitation

Aims: To evaluate the correlation of the flow patterns of the four pulmonar y veins as assessed by transesophageal echocardiography and the influence o f significant mitral regurgitation on this correlation. Methods and Results : Eighty-eight patients with normal sinus rhythm and variable underlying ca rdiovascular diseases underwent transthoracic and transesophageal echocardi ographic studies, Doppler flow of the four pulmonary veins could not be ade quately interpreted in 19 patients (22%). The left atrial dimension of thes e patients was significantly larger than that of the patients with complete study of the flow in the four pulmonary veins (49 +/- 6 vs. 43 +/- 7 mm; p < 0.05). Of the 69 patients with complete evaluation of the four pulmonary veins, 48 patients without significant mitral regurgitation were analyzed as group A, and the remaining 21 patients as group B. The peak systolic and diastolic forward flow velocities of the four pulmonary veins were measure d and the ratio of peak systolic (S) to diastolic (D) flow velocity was cal culated. Group A had a significantly larger S/D ratio in all four pulmonary veins than group B (p < 0.05 in each pulmonary vein measurement). There wa s good correlation of the flow pattern represented as S/D ratio between lef t upper and lower pulmonary veins (r = 0.90) and between right upper and lo wer pulmonary veins (r = 0.89) in group A. The correlation of the flow patt ern among the four pulmonary veins deteriorated in group B. Conclusion: Pul monary veins on the same side share rather similar flow patterns in compari son with pulmonary veins on the opposite sides, The correlation of flow pat terns among the four pulmonary veins is good in subjects without significan t mitral regurgitation, but it worsens in patients with significant mitral regurgitation. Therefore, cautious interpretation of flow patterns of the f our pulmonary veins in patients with significant regurgitation is indicated for grading the severity of mitral regurgitation.