Figure 199f

External sound, equisensitive left ventricular and left atrial pressures ( catheter -tipped micromanometer) left ventricular dP/dt and left atrialsound arerecorded simultaneously with the mitral valve echocardiogram in a patient with hemodynamically significant mitral stenosis. Asignificant presystolic gradient is present due to atrial contraction, and the onset of the rapid closure of the mitral valve (B) is delayed until the left ventricular pressure exceeds the left atrial pressure.This occurs 40ms after the beginning of the left ventricular pressure rise at a time when left ventricular dP/dtD is much higher than normal. Following left atrial-left ventricular pressure crossover, thereis rapid ventricular genic closure of the mitral valve (B-C) resulting in a very loud M1 coincident with the C point of the mitral valve echocardiogram and the downstroke of the c wave of the lefty arial pressure. The prominent opening snap is coincident with the E point of the mitral valve echocardiogram. Its separation fromA2 is determined by both the level of the left atrial pressure and the rate of the left ventricular pressure decline.