Plasma noradrenaline as an indicator of functional state in hearts with mitral stenosis: the influence of acutely reduced left atrial pressure by balloon mitral commissurotomy

Changes of urinary dopamine excretion early after balloon mitral commissurotomy in mitral stenosis

1. In order to investigate the changes of reduced urinary free dopamine excretion (uDA) in heart failure, 15 patients with symptomatic mitral stenosis were investigated on their uDA, endogenous creatinine (Cr) clearance, urinary excretion of sodium (UNaV), fractional excretion of sodium (FENa), plasma noradrenaline (pNA) and plasma L-dopa concentration before and early after percutaneous transvenous mitral commissurotomy (PTMC) by the clearance study. The delivery of L-dopa to renal proximal tubules (plasma L-dopa x Cr clearance), and the conversion ratio of plasma L-dopa to urinary dopamine in the kidney [uDA/(plasma L-dopa x Cr clearance)] were also estimated. 2. After successful PTMC, uDA, UNaV and FENa showed a significant but incomplete improvement and the changes of uDA were correlated positively with those of cardiac index (CI) (r = 0.665, P < 0.01), not with changes of pulmonary wedge pressure. While plasma L-dopa and plasma L-dopa x Cr clearance improved, uDA/(plasma L-dopa x Cr clearance) was not significantly changed early after PTMC. 3. From these results, it was suggested that reduced uDA tended to increase incompletely in relation with functional recovery of heart, and that increased plasma L-dopa and a delivery of L-dopa to renal proximal tubules have some positive role on urinary dopamine excretion, at least, early after PTMC.

Plasma concentrations of adrenomedullin correlate with the extent of pulmonary hypertension in patients with mitral stenosis

OBJECTIVE

To examine the pathophysiological significance of adrenomedullin in the pulmonary circulation by investigating the relation between plasma concentrations of adrenomedullin and central haemodynamics in patients with mitral stenosis.

METHODS

Plasma concentrations of adrenomedullin in blood samples obtained from the femoral vein, pulmonary artery, left atrium, and aorta were measured by a newly developed specific radio-immunoassay in 23 consecutive patients with mitral stenosis (16 females and seven males, aged 53 (10) years (mean (SD)) who were undergoing percutaneous mitral commissurotomy.

RESULTS

Patients with mitral stenosis had higher concentrations of adrenomedullin than age matched normal controls (3.9 (0.3) v 2.5 (0.3) pmol/l, p < 0.001). There was a reduction in adrenomedullin concentrations between the pulmonary artery and the left atrium (3.8 (0.2) v 3.2 (0.4) pmol/l, p < 0.001). The venous concentrations of adrenomedullin correlated with mean pulmonary artery pressure (r = 0.65, p < 0.001), total pulmonary vascular resistance (r = 0.83, p < 0.0001), and pulmonary vascular resistance (r = 0.65, p < 0.001). Plasma concentrations of adrenomedullin did not change immediately after percutaneous mitral commissurotomy; however, they decreased significantly one week later.

CONCLUSIONS

Plasma concentrations of adrenomedullin are increased in patients with mitral stenosis. This may help to attenuate the increased pulmonary arterial resistance in secondary pulmonary hypertension due to mitral stenosis.