Left atrial compliance and pulmonary venous flow velocities are related to functional status in patients with moderate-to-severe mitral stenosis

In mitral stenosis (MS), left atrial (LA) compliance plays a crucial role in the occurrence of symptoms and pulmonary arterial hypertension and can alter pulmonary venous flows (PVF). The aim of present study is to compare LA compliance (net atrioventricular compliance-Cn) and PVF velocities in patients with different functional status despite similar mitral valve area (MVA). Additionally, the relationships of the same variables with each other and other echocardiographic parameters showing the hemodynamic severity of mitral stenosis were investigated.Thirty-one patients with moderate to severe mitral stenosis were studied. The patients were divided into two groups according to their NYHA functional classes (FC). The patients with lower FC (NYHA FC1 and FC2) were included in Group I(n = 15), and those with FCor = 3 included in Group II (n = 16). All patients underwent comprehensive transthoracic and transesophageal echo Doppler examination.Despite similar LA size, MVA, and transmitral diastolic pressure gradients, systolic pulmonary artery pressure (SPAP) was significantly higher and LA compliance was significantly lower in Group II as compared to group I. Also, systolic PVF velocity (PVs), diastolic PVF velocity (PVd), and PVs/PVd ratio were significantly lower in Group II as compared to Group I. In whole group, significant positive correlations between LA compliance and PVs (r = 0.38, P = 0.035), as well as PVd (r = 0.40, P = 0.023) and, significant negative correlation between LA compliance and SPAP (r =- 0.36, P = 0.047) were noted.Our findings suggested that in patients with MS, when there is inconsistency between symptomatic status and conventional echocardiographic variables, simple and noninvasive Doppler parameters, LA compliance, and PVF could be measured before cardiac catheterization for more accurate and complete evaluation of patients.