Movement of the mitral valve and its correlation with the first heart sound. Selective valvular visualization and high-speed cineradiography in intact dogs.

Abstract

Movement of the mitral valve was studied in six intact dogs by coating the valve cups selectively with an adhesive radiographic contrast material (ACM) during high-speed cineradiographic (270 fps) filming. The heart sounds were recorded simultaneously on the reverse side of the same film. The movement of the valvular structures was analyzed using a digitizing table and a computer programmed to provide displacement and velocity data and to correlate them with the heart sounds. It was concluded that: 1. The ACM provides an accurate selective radiographic delineation of the heart valves in intact dogs. 2. The movement of the mitral valve does not start with the free margins, but rather with the center of the cusps. The cusps exhibit a mobile curved configuration throughout the cycle, appearing as a traveling wave. The opening peak velocities of the valvular edges reached 45-50 cm/sec; the peak closing velocity ranged from 50-60 cm/sec. 3. The second component of the first heart sound invariably coincided with the incident of greatest deceleration of the mitral valve during its closing motion.