PURPOSE: We compared adults with mitral stenosis (MS) to 8 controls (CONT) to see how pulmonary impedance and wave reflections differ at baseline and after balloon valvuloplasty. METHODS: We separated the MS patients into groups according to mean pulmonary artery pressure: moderate (MOD
≤ 26 mmHg, n = 21) and high (HIGH
>
26 mmHg, n = 33). We made baseline high-fidelity measurements in all patients, in the MS groups after vasodilation with nitroprusside, immediately and 4 months after balloon valvuloplasty. RESULTS: Comparing MOD vs CONT, using the Kruskal-Wallis test with Bonferroni correction, reveals evidence for higher baseline input resistance (R) (489 vs 205 dyne-sec/cm CONCLUSION: MS causes alterations in pulmonary hemodynamics that differ according to pressure levels. These changes are only partially reversed immediately after valvuloplasty. There is evidence for reverse remodeling 4 months afterwards.