[An evaluation of the pulmonary venous flow pattern by transesophageal and transthoracic Doppler echocardiography in a normal subject].

Transesophageal echocardiographic studies have permitted a pulmonary venous flow velocity pattern to be identified which is comparable to that recorder using invasive methods. The pattern consists of 4 stages: an anterograde systolic flow with an early (S1) and late (S2) peak velocity, a diastolic anterograde flow (D) and a retrograde flow liked to atrial contraction (Ar). The aim of this study was to evaluate the pattern of pulmonary venous flow velocity using transesophageal and transthoracic colour Doppler echocardiography in normal subjects in an attempt to: 1) determine normal values derived from the pulmonary venous flow pattern which may contribute to future studies; 2) find correlations between the pattern of pulmonary venous flow and a number of physiological, hemodynamic and echocardiographic parameters which take account of the morphological variations of this flow pattern within a normal range; 3) demonstrate the possibility of being able to carry out study using transthoracic colour Doppler echocardiography. The study was carried out in 38 normal subjects aged between 15 and 76 years old (mean 45 +/- 15) who underwent transthoracic and transesophageal colour-Doppler echocardiography. The following parameters were measured: left atrium diameter, diameters and telediastolic and telesystolic volumes of the left ventricle, ejection fraction and systolic percentage shortening of the left ventricle, peak velocity of the mitral flow pattern and the pulmonary venous flow pattern. The results obtained show that: 1) the pattern of pulmonary venous flow alters with ageing causing the prevalence of systolic over diastolic peak velocity; 2) the pulmonary venous flow parameters which appear to be most significant in hemodynamic terms are the peak velocities of the early systolic flow and anterograde diastolic flow and the ratios S1/S2 and S2/D; 3) the echocardiographic parameters most closely correlated with the peak velocity of pulmonary venous flow are the dimensions of the left atrium, telediastolic and telesystolic ventricular volumes, and the pattern of transmitral flow; 4) heart rate does not appear to influence the pulmonary venous flow pattern significantly (at least within the range of 50-100 b/min), except for retrograde flow. Similar results were obtained using transesophageal and transthoracic Doppler echocardiography and therefore if future studies succeed in obtaining useful information, of not only speculative but also practical interest, from the evaluation of pulmonary venous flow, these can be obtained using a simple, widespread and completely non-invasive method such as transthoracic Doppler echocardiography.