title: Atrioventricular pressure half-time. Measure of mitral valve orifice area.
abstract: 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.
authors.affiliation: Department of Cardiology, Division of Medicine, City of Hope Medical Center, Duarte, California, USA.
authors.forename: A J
authors.initials: AJ
authors.lastname: Libanoff
authors.forename: S
authors.initials: S
authors.lastname: Rodbard
mesh_terms: D002932:Cineangiography; D003971:Diastole; D005080:Exercise Test; D006350:Heart Valve Prosthesis; D006801:Humans; D008944:Mitral Valve Insufficiency / Q000175:diagnosis / Q000503:physiopathology* / Q000601:surgery*; D017725:Ventricular Pressure