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 exc retion (uDA) in heart failure, 15 patients with symptomatic mitral stenosis were investigated on their uDA, endogenous creatinine (Cr) clearance, urin ary excretion of sodium (UNaV), fractional excretion of sodium (FENa), plas ma noradrenaline (pNA) and plasma L-dopa concentration before and early aft er percutaneous transvenous mitral commissurotomy (PTMC) by the clearance s tudy. 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 i n the kidney [uDA/(plasma L-dopa x Cr clearance)] were also estimated. 2. After successful PTMC, uDA, UNaV and FENa showed a significant but incom plete improvement and the changes of uDA were correlated positively with th ose of cardiac index (CI) (r = 0.665, P <0.01), not with changes of pulmona ry wedge pressure, While plasma L-dopa and plasma L-dopa x Cr clearance imp roved, uDA/(plasma L-dopa x Cr clearance) was not significanfly changed ear ly 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 incre ased 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 PTM C.