Influence Of Myocardial Motion By Different Pacing Sections Of Right Ventricular

Objective: We sought to measure quantitatively the peak time of myocardial motion by different pacing sections of right ventricular at each segments and phases, as well to compare relevant parameters of contractile and diastolic function, analyze the synchronism of myocardial motion, evaluate the effect of myocardial motion by different pacing sections, by use of Doppler Tissue Imaging(DTI) and the Quantitative Tissue Velocity Imaging (QTVI) which is based on the DTI.Methods: We selected 20 patients by right ventricular apex (RVA) pacing and 20 patients by right ventricular septum (RVS) pacing; recorded the simultaneous ECG with magnetic-frequency in quiescent condition, collected and saved the Doppler imaging of Apical four chamber view, Apical two chamber view and the left ventricular long axis view in the TVI mode, got the time-speed curve of the movement of right ventricle lateral wall, interventricular septum and left ventricle lateral wall through the Apical four chamber view, got the time-speed curve of the movement of left ventricle anterior wall, inferior wall, left ventricle anterior septal, posterior wall through Apical two chamber view and the left ventricular long axis view, measure the interval of contractile and diastolic time at basal and middle parts of left and right ventricle, and evaluated the variation of myocardial motion by RVA and RVS pacing.Results:①Systole and diastole peak time: In RVA group ,the systole peak time delayed obviously but the diastole peak time was shorten in some segements listed above comparing with RVS group, P<0.05,the difference has statistical significance,especially the left ventricle lateral wall, inferior wall and posterior wall.②Electro-synchronism and mechanical systole synchronism: the RVA group compared with RVS group, the time of QRS wave is wider, it is 0.129±0.014s vs 0.152±0.022s P<0.01,it has significant difference; mechanical systole synchronism is lower in the left ventricle and the biventricular. the dispersion of systole peak time in the left ventricle Ts—SD(standard deviation of systole peak time of deferent left ventricle segments in one cardiac cycle) and the range of systole peak time in the left ventricle Ts—maxD(the equation of maximal value and minimum value of systole peak time of deferent left ventricle segments in one cardiac cycle), the RVA group compared with RVS group, in the left ventricle, it is 0.044±0.010s vs 0.033±0.005s P=0.001<0.01 and 0.124±0.022s vs 0.102±0.123s P=0.003<0.01, the difference has statistical significance; between the left ventricle and the right ventricle, it is0.046±0.013s vs 0.032±0.012s P=0.005<0.01 and 0.109±0.031s vs 0.078±0.029s P=0.010<0.05, the difference has statistical significance.③The segments which show the Post-systolic shortening and D-wave in the phase of diastasis: the RVA group is more than the RVS group. It is 20.71% vs 6.79%;33. 21% vs 16.79% P<0.001,the difference has statistical significance.Conclusion: The pacing sections play an important role in synchronism of ventricle systole and diastole, the RVS pacing compared with the RVA pacing, has more advantages in keeping the electro-synchronism and mechanical systole synchronism.