Neurohormones in mitral stenosis before and after percutaneous balloon mitral valvotomy

The hormonal response to percutaneous balloon mitral valvotomy (PBMV) has been described in patients in sinus rhythm (SR) and with atrial fibrillation (AF). The study aim was to evaluate the effect of hemodynamic parameters and PBMV on atrial natriuretic factor (ANF) secretion and plasma renin activity (PRA) in mitral stenosis in SR and AF.

Thirty-one patients (26 females, five males; mean age 50.5+/-14 years) with pure rheumatic mitral stenosis underwent PBMV. Fourteen patients had AF, and 17 were in SR. PRA and ANF were measured 24 h before, and at 30 and 60 min, 24 h and one month after PBMV, after resting in a supine position for > or =2 h. Digitalis and diuretics were withdrawn 48 h before sampling; neither had patients received ACE inhibitors or beta-blockers during the previous month.

PBMV was successful in all cases, without complication. Mitral valve area was increased and wedge pressure decreased in both groups after PBMV. In AF patients, neither PRA nor ANF were significantly affected before and after PBMV; in SR patients, ANF was decreased and PRA increased significantly, notably 24 h after PBMV. The cardiac index was increased in both groups, but was distinctly lower in AF patients both before and after PBMV.

Despite similar hemodynamic results, reversal of the hormonal pattern after PBMV occurred only in SR patients, most likely because in AF patients a low cardiac index elicits a hormonal response similar to heart failure. This abnormal hormonal pattern may limit functional recovery after PBMV; hence, PBMV is best attempted while patients are still in SR.