A method and a device for determining a cardiac function parameter, the device including a sonic sensor for determining timing data of a closure of a mitral valve and an aortic valve, a pressure cuff and a sensing unit coupled to the pressure cuff for sensing. The sensing unit is configured to sense, for each cardiac cycle, blood breakthrough pressure data and corresponding time data from a closing of the mitral valve and data relating to a velocity of propagation of a pressure wave as it travels along at least a portion of the pressure cuff. The device also includes a processing unit for determining a value of at least one cardiac function parameter based on the data.