Atrioventricular pressure half-time varied inversely with mitral valve orifice area, measuring approximately 100 msec in mild, 200 msec in moderate, and ≥300 msec in severe mitral stenosis.
Observational (n=20)
In 20 patients studied by cardiac catheterization, the time required for the diastolic left atrioventricular pressure difference to fall to half its initial value (half-time) varied with the anatomic severity of the valvular stenosis. In mild mitral stenosis, the half-time was approximately 100 msec; in moderate stenosis, it was about 200 msec; and it was 300 msec or longer in severe stenosis. The half-time at the nonstenotic mitral valve was less than 25 msec. Although exercise increased the atrioventricular pressure gradient, heart rate, and cardiac output significantly, the half-time was affected only slightly. Mitral regurgitation of various severities did not affect the half-time. The half-time appears to vary inversely with the anatomic orifice area of the mitral valve. The determination of the half-time obviates the need for the commonly used exercise test for the evaluation of mitral stenosis.
Libanoff et al. (Mon,) conducted a observational in Mitral stenosis (n=20). Atrioventricular pressure half-time measurement was evaluated on Atrioventricular pressure half-time. Atrioventricular pressure half-time varied inversely with mitral valve orifice area, measuring approximately 100 msec in mild, 200 msec in moderate, and ≥300 msec in severe mitral stenosis.