The current invention is an intracardiac pressure guided pacemaker. It has a sensor in pacemaker lead to sense intracardiac pressure, which is used to find the best pacing location in the
cardiac chamber and to adjust the timing of pacing
signal. It will optimize pacing location and pacing timing and, therefore, optimize resychronization of the contraction of myocardium and interaction between different cardiac chambers. This will improve cardiac function at the same working condition without increase in
oxygen demand from myocardium. The pacemaker has a
computer program, which, based on intracardiac pressure, can adjust pacing parameters of the pacemaker to optimize resynchronization of the myocardium and interaction between different cardiac chambers automatically at different
heart rate and in certain time interval specified by care provider. This also can be achieved by using an interrogator manually. The pacemaker can also store profiles of pacing parameter and intracardiac pressure, which can be retrieved for review to help optimize cardiac performance.