A NOTE ON MITRAL-VALVE MECHANICS - A PRE-STRESSED LEAFLET CONCEPT

Mechanical properties of human mitral valve leaflets are reviewed Stress-strain characteristics of pre- and post-transitional elastic stretch are examined. Model [2] relating ventricular pressure to leaflet stress are presented to predict the onset of leaflet transition during early systole. A general biomechanical model of the valve leaflet is examined 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 apparently accounts for this condition.