Transesophageal Doppler Echocardiographic Pattern of Pulmonary Venous Flow in Severe Mitral Stenosis

Abstract

Objectives: Analysis of the pulmonary venous flow enables an evaluation of cardiac hemodynamics. This study was conducted to evaluate the effect of severe mitral stenosis on the pulmonary venous flow both in sinus rhythm and atrial fibrillation. Methods: We studied 38 patients with isolated severe mitral stenosis (mitral valve area index ≤0.75 cm²) by pulsed wave Doppler transesophageal echocardiography of the left upper pulmonary vein. Twenty-six patients (68%) were in sinus rhythm and 12 (32%) in atrial fibrillation. Results: The peak systolic flow velocity was significantly lower in atrial fibrillation patients with blunted systolic flow pattern in 67%, while the normal flow pattern with higher systolic-to-diastolic flow ratio was found in 69% of sinus rhythm patients. Pulmonary venous flow was significantly delayed in its onset and termination with atrial fibrillation compared to sinus rhythm even after correction for heart rate (p < 0.02, p < 0.04, respectively). The pulmonary venous peak systolic flow velocity showed a significant negative correlation with the mean pulmonary pressure (r = –0.424, p = 0.011). Finally, there was a correlation between the pulmonary venous diastolic pressure half-time and the peak mitral gradient (r = –0.327, p = 0.045), mean mitral gradient (r = –0.369, p = 0.022) and Doppler mitral valve area (r = –0.422, p = 0.008). Conclusion: Severe mitral stenosis is associated with a decreased pulmonary venous systolic flow and prolonged decay of the diastolic flow, and these changes are more marked in atrial fibrillation. These results can help to understand the hemodynamics of mitral stenosis and its interaction with the pulmonary circulation.