Abnormalities of left ventricular filling in valvular aortic stenosis. Usefulness of combined evaluation of pulmonary veins and mitral flow by means of transthoracic Doppler echocardiography

Abstract

It has been recently demonstrated that indexes obtained from the study of pulmonary venous flow by Doppler echocardiography are related to left ventricular (LV) pressures during diastole and may improve the assessment of LV filling derived from analysis of mitral flow velocities. In this study we evaluated the pattern of pulmonary venous flow and transmitral flow by means of transthoracic pulsed Doppler echocardiography in 31 adult patients (11 females, 20 males, mean age 72 ± 10 years) with valvular aortic stenosis (Doppler valve area: 0.77 ± 0.17 cm 2) and in 15 age-matched normal subjects (five females, 10 males, mean age 68 ± 6 years). Doppler indexes of mitral flow were similar between the two groups; on pulmonary venous flow, peak systolic velocity was lower (46 ± 13 vs. 63 ± 17 cm/s, P < 0.01) and both duration of reversal flow during atrial systole and difference between pulmonary atrial reversal flow and mitral A wave duration were longer in aortic stenosis patients compared to normals (148 ± 21 vs. 111 ± 16 ms and 6 ± 27 vs. −26 ± 21 ms, respectively, P < 0.001). Twenty-two aortic stenosis patients showed an early to late mitral flow ratio (E/A) ≤ 1 and the remaining nine patients had a E/A > 1. Patients with E/A ≤ 1 showed, compared to those with E/A > 1, a significant prolongation of deceleration time of early filling (242 ± 76 vs. 127 ± 32 ms, P < 0.001) and, on pulmonary venous flow, a higher peak systolic and lower peak diastolic velocity (52 ± 9 vs. 33 ± 12 cm/s and 37 ± 8 vs. 56 ± 10 cm/s, respectively, P < 0.001), determining a significantly lower diastolic to systolic velocity ratio (D/S: 0.7 ± 0.14 vs. 1.9 ± 0.9, P < 0.001). Also, the duration difference between pulmonary atrial reversal flow and mitral atrial systole wave was significantly different between the two groups (−6 ± 21 ms in patients with E/A < 1 vs. 35 ± 15 ms in those with E/A > 1, P < 0.001); furthermore, this difference was negative in 15 and positive in seven patients with E/A < 1, while it was always positive in patients with E/A > 1. All patients with E/A > 1 had symptoms of congestive heart failure, often severe and associated to a reduction of LV systolic function. In the other group, nine out of 22 patients had heart failure; it was usually mild and associated to a preserved LV systolic function. In conclusion, in patients with valvular aortic stenosis the combined evaluation of pulmonary venous and mitral flow may allow the recognition of different patterns of LV filling; they probably reflect different values of LV filling pressure and may contribute to the noninvasive identification of the hemodynamic profile in the single patient.