Abstract: Apparatus and methods for improving the ventricular activation sequence of the heart by pacing at an advantageous selected ventricular location to achieve shortening of the QRS complex or pacing at multiple advantageous selected ventricular locations, either simultaneously or with a programmed delay or delays between firings, to achieve shortening of the QRS complex in combination with producing a desirable and efficient ventricular motion. During a cardiac cycle initiated by intrinsic cardiac activity, stimulating impulses may be directed to advantageous selected locations of the ventricles by employing intrinsic cardiac signals to trigger the stimulating impulses, either simultaneously or with a programmed delay or delays between the sensed event or events and firing event or events, to provide improved mechanical and electrical ventricular function.

Abstract: Apparatus and methods for improving the ventricular activation sequence of the heart by pacing at an advantageous selected ventricular location to achieve shortening of the QRS complex or pacing at multiple advantageous selected ventricular locations, either simulataneously or with a programmed delay or delays between firings, to achieve shortening of the QRS complex in combination with producing a desirable and efficient ventricular motion. During a cardiac cycle initiated by intrinsic cardiac activity, stimulating impulses may be directed to advantageous selected locations of the ventricles by employing intrinsic cardiac signals to trigger the stimulating impulses, either simultaneously or with a programmed delay or delays between the sensed event or events and firing event or events, to provide improved mechanical and electrical ventricular function.

Abstract: An artificial heart valve of turbine-like construction includes a rotor that translates and rotates to cause a plurality of rotor blades to either occlude or unocclude spaces between adjacent ones of a plurality of stator blades.