简介：ObjectiveTodeterminewhethersuccessfulvalvuloplastycausesanincreaseofmitralvalveareareserveinpatientswithmitralstenosis,isoproterenolstressechocardiographywasusedtocomparemitralvalveareaandhemodynamicchangesbetweenpre-andpost-valvuloplastyunderconditionsofincreasedcardiacwork.MethodsThirty-eightpatientswithpurerheumaticmitralstenosiswhohadreceivedsuccessfulpercutaneousballoonvalvuloplastyunderwentisoproterenolstressechocardiographypre-andpost-valvuloplasty.Mitralvalvearea(bydirectplanimetryoftwo-dimensionalechocardiography),meantransmitralpressuregradient(bycontinuous-waveDopplerechocardiography),andcardiacoutput(byM-modeechocardiography)weremeasuredatrestandunderisoproterenolstresstoachieveheartrateofdifferentstages.ResultsMitralvalvearea(0.91±0.28to1.87±0.23cm2,P<0.01),meantransmitralpressuregradient(12.5±6.3to3.9±1.9mmHg,P<0.01)andcardiacoutput(3.93±1.44to4