Abstract： AIM:To observe the influences on myocardial coordination when pacing with electrode on different spots in therapy with pacemaker.METHODS:Using Tissue Doppler velocity,we observed the 48 patients who received pacemaker implantation,including 28 of right ventrieular outflow tract pacing(RVOTP)and 20 of fight ventricular apical pacing(RVAP),collected data of the cardiac muscle movements of left ventricle during theirs eight stages.Each stage consists of:1.time-to-peak of myocardial contraction,2.time-to-peak of diastolic rapid filling,3.myocardial contraction time.With the data above we can get the influences on myocardial coordination when pacing with electrode on different spots.RESULTS:For patients in group RVOTP and RVAP,when comparing the time-to-peak of myocardial contraction,which reflect the coordination of myocardial contraction,we can con-clude that:there was no significant difference between the two sets of data before pacemaker implantation,but 3 to 6 months later coordination of the RVOTP group markedly improved(P<0.01)while that of the RVAP group declined(P<0.01),the coordination of the former obviously exceeded the latter(P<0.01).When comparing the time Q-E,which reflect the coordination of diastolic movement,we can conclude that:there was no significant difference between the two sets of data before pacemaker implantation,but the coordination of RVAP group declined after the period of 3 to 6 months(P<0.01)and markedly below that of the RVOTP group(P<0.01).CONCLUSION:Using spiral electrodes to select the ideal pacing spots can be conducive to the coordination of myocardial contraction.