A note on mitral valve mechanics: A pre-stressed leaflet concept

The mechanical properties of the mitral valve leaflets are reviewed. Stress-strain characteristics of both pre- and post-transitional elastic stretch are examined. Two models relating ventricular pressure to leaflet stress are presented in order to predict the onset of leaflet transition during early systole. A general biomechanical model of the valve leaflet is examined in order to explain the lack of detectable elastic stretch in radiographic data. The relatively large elastic stretch of the pre-transition phase of the mechanical model is neglected so that the predicted stretch can confirm to physiological data. A condition of continual tension in the valve leaflet which induces a post-transitional stress throughout the cardiac cycle is assumed to account for this condition.