In vivo analysis of aortic valve dynamics by transesophageal 3-dimensional echocardiography with high temporal resolution

Objectives: Knowledge of aortic valve function has been obtained from experimental studies. The aim of the present study was to investigate characteristics of aortic valve motion in humans. Methods: Fifty-six patients were studied: 19 with normal valve and good systolic left ventricular function (Group NL), 12 with normal valve and reduced left ventricular function (Group CMP), and 25 with aortic stenosis and good left ventricular function (Group AS). The frame rate was doubled (50 Hz) compared with previous 3-dimensional systems. A mean of 38 +/- 9 images were acquired per cardiac cycle, with 14 +/- 4 images during the systole. The changes in shape and orifice area were analyzed over time. Results: With normal valves, valve movement proceeded in 3 phases: rapid opening, slow closing, rapid closing. Stenotic valves showed a slower opening and closing movement. The times to maximum opening in Groups NL, CMP, AS were 76 +/- 30, 88 +/- 18 (P = .06), and 130 +/- 29 (P < .01) ms, respectively. It was inversely correlated to the maximum orifice area (r = -0.59, P < .001). The opening velocities in Groups NL, CMP, AS were 42 +/- 23, 28 +/- 9 (P < .05), and 5 +/- 2 (P < .001) cm(2)/s, respectively. There was a close correlation between the opening velocity and the maximum orifice area (r = 0.87, P < .001). Slow valve closings occurred at a velocity of 8.0 +/- 5.2, 5.3 +/- 2.0 (P = .21), 2.8 +/- 1.1 (P < .01) cm(2)/s, respectively, and rapid closings in Groups NL and CMP at 50 +/- 23, 29 +/- 8 (P < .01) cm(2)/s. The results show good agreement with experimental data. Conclusion: Rapid aortic valve movement can be recorded by 3-dimensional echocardiography and analyzed quantitatively. Time and velocity indices of valve dynamics are influenced by valvular and myocardial factors. A comparable in vivo analysis is not possible with any other imaging procedure.