Ultrasound imaging methods and systems for assisting a clinician in configuring the operation of a pacemaker and for determining an optimal site for the pacemaker electrode are presented. The methods and systems provide a toolbox for analyzing and optimizing the effectiveness of the pacemaker and proposed electrode sites. The method includes a function which evaluates one or more electrode sites and pacemaker configurations. The function may be based, for example, on the activation voltage of the pacemaker, on an estimate of the volume of blood ejected from the heart and/or on the cardiac dysynchrony. The ejection volume and the dysynchrony may be estimated using an imaging cardiac catheter ultrasound transducer array and ultrasound unit.