Pulmonary venous flow in pure mitral stenosis and sinus rhythm - Does pulmonary hypertension alter pulmonary venous flow velocity?

Pulmonary venous flow (PVF) is influenced by changes in left atrial (LA) pressure and function in various diseases. In mitral stenosis (MS), there is an alteration of LA hemodynamic due to the impaired ventricular filling caused by the stenotic valve and elevation of LA pressure. Although a variety of altered patterns of PVF have been described in MS, the potential influence of pulmonary hypertension, which is frequently associated with MS and has an adverse effect on the functional status and the prognosis of MS, on the PVF pattern is not clearly defined. The aim of this study is to determine the effects of pulmonary hypertension on PVF in patients with MS. Thirty-eight consecutive patients with pure MS and sinus rhythm (30 females, mean age 40 years old) underwent transthoracic and transesophageal echocardiography. Right heart and transseptal catheterization was also performed to measure pulmonary artery systolic pressure (PASP), pulmonary artery diastolic pressure (PADP), pulmonary capillary wedge pressure (PCWP), and left atrial pressure (LAP). The subjects were divided into two groups:group 1 (n = 25) included subjects with PASP < 50 mmHg, group 2 (n = 13) included subjects with PASP 50 mmHg. LA size, mitral valve area (MVA), mean mitral gradient (MG), LAP, PASP, PADP, PCWP, and the peak velocity of PV systolic (PVFS), diastolic (PVFD) and atrial reversal flow (PVFAr) were also measured and compared between the two groups. There was no significant difference in age, heart rate, MVA, and LA size between the two groups. LAP, PASP, PADP, PCWP, and MG were significantly higher in group 2. However, PVFS and PVFAr were significantly lower in group 2 (46.6 ± 15.8 vs 29.9 ± 12.8 cm/sec, P < 0.005;22.1 ± 6.8 vs 17.3 ± 5.9 cm/sec, P < 0.05). There was no significant difference of PVFD between the two groups. PVFS had negative correlation to LAP, MG, PASP, PADP, and PCWP. PVFAr had negative correlation with PASP, PADP, and PCWP. There was no significant correlation between PVFAr and MVA, LA size and LAP. In conclusion, in patients with pure MS and sinus rhythm, PVF, especially PVFAr, is influenced by the presence of pulmonary hypertension.