[Echocardiographic study of mitral and tricuspid valve openings in normal subjects (author's transl)]

The purpose of the present echocardiographic study is to determine the timing and order of both mitral and tricuspid valve openings in normal subjects and to provide the basic data for evaluating diastolic hemodynamics in cardiac patients. The subjects consisted of three groups: (i) 30 normal young cases in which the opening of both valves was recorded, (ii) 8 cases with idiopathic atrial fibrillation in which the relationship between preceding R-R and early diastolic intervals was determined, and (iii) 10 cases in which the effect of the direction of the ultrasonic beam on mitral valve echograms was evaluated. By applying dual echocardiography or phonoechocardiography, the interval from the aortic component of the second heart sound (IIA) to the point of maximal anterior opening (E), the isovolumic relaxation period from IIA to the onset of opening (D') and opening slope of the anterior leaflet were measured in each valve echogram. Careful recording was mandatory for measurements because even slight angulation of the transducer toward the mitral ring induced the timing of D' point and opening slope to vary. Respiratory variation was observed on the movements of both valves. During inspiration mitral valve opening occurred further from IIA or did not change in timing, but the tricuspid valve opened prematurely. During expiratory phase, the mitral valve opened nearly simultaneously with the tricuspid valve. The measurements were: IIA-E interval = 99.8 +/- 13.1 (mean +/- SD), 104.5 +/0 20.6 msec; IIA-D' interval = 47.2 +/- 9.9, 48.3 +/- 13.1 msec; opening slope = 301 +/- 76, 264 +/- 59 mm/sec, in mitral and tricuspid valve echograms, respectively. In cases with atrial fibrillation, these measurements were nearly constant regardless of varied preceding R-R intervals in 8 mitral and in one tricuspid valve echograms. It was expected from observing the effect of R-R intervals on valve opening in a case of valvular disease that diastolic hemodynamics could be evaluated by analysing the timing and order of both valvular openings, especially in relation to the preceding R-R intervals in atrial fibrillation.