In mitral stenosis with atial fibrillation, it is known that there is a significant linear correlation between end-diastolic mitral pressure gradient(EDMG) in cardiac catheterization and the corresponding RR interval. And using this, the equations to calculate the mitral valve area(MVA) in several heart retes has been inducing. However, as cardiac catheterization has a limitation not to be practiced repeatedly in all patients due to invasive procedure. In this study, using transthoracic doppler echocardiography, we tried to investigate the correlation of EDMG, RR interval and MVA and we tried to get the nomogram to predict MVA in different heart rates using it.

We made 9 patients an abject of this study whose measured MVA is from 0.5cm² to 1.55cm² by pressure half time(PHT) method among patients who have no any valvular heart disease except mitral stenosis with atrial fibrillation and whose condition is stable. We investigated the linear correlation between EDMG and RR interval, RR interval=a×EDMG+b(a ; slope, b ; intercept), using doppler echocardiography. We got the equation and nomogram to make an estimate of MVA with multiple regression analysis using the relation of measured MVA, slope and intercept.

There was a linear correlation between EDMG and RR interval in all the patients. There was a mutual correlation of slope=53.0×(measured MVA)−101.2 between measured MVA and slope. There was a negative correlation of intercept=1,497−470×(measured MVA) between measured MVA and intercept. Using these, we could get multiple regression analysis equation, estimated MVA=0.0113×slope−0.0007×intercept+2.2497 and nomogram to estimate MVA.

We could get the nomogram to estimate MVA easily using doppler echocardiography in mitral stenosis with atrial fibrillation.