[Pulmonary venous compliance. Indirect evaluation based on pulmonary capillary pressure registration]

The compliance of pulmonary venous system (PV comp) is one of the most important factors influencing left ventricular filling pressure. The decrease of PV comp could be also one of the most important factors promoting secondary pulmonary hypertension. The aim of the study was to assess diagnostic value of PV comp based on some haemodynamic data in patients (pts) with isolated mitral stenosis (MS). PV comp was estimated according to Hirakawa equation (dV/dP = 0.4 * k2 x SV/(v - d), where k2 = 0.075 * PWP + 0.9) in 78 pts with MS, during preoperative right heart catheterisation with Vygon 5155-180 thermodilution catheters. The mean PV comp for the entire group of pts was 4.5 +/- 2.4 ml/mmHg. In pts with atrial fibrillation PV comp was significantly lower as compared with pts on sinus rhythm (3.7 +/- 1.9 vs 6.4 +/- 2.3, p < 0.0001. There was also a significant difference between NYHA I/II vs III/IV class as far as PV comp was concerned (5.1 +/- 2.3 vs 3.9 +/- 2.3, (p < 0.05). In the group with low PV comp less than 4 ml/mmHg pulmonary vascular resistance, RA, PA and amplitude of V-wave of PWP were significantly higher and stroke volume index of RV was lower than in the group with PV comp above 4 ml/mmHg. PWP did not differentiate the analysed groups. A decrease of PV comp is a sign of advanced mitral stenosis.