Objective To evaluate the influence and mechanism of different cardiac pacing modes on TCM syndrome manifestations and hemodynamics of sick sinus syndrome（SSS）.Methods The 75 SSS patients were detected syndrome manifestation scores and hemodynamic parameters before operations and 1 month after pacing to compare the differences among the different cardiac pacing modes.Results After operations

the syndrome manifestation scores were all decreased（P < 0.05）.Compared with VVI group

the improvement of hemodynamic parameters was statistically significant in AAI and DDD groups in left ventricular ejection fraction（LVEF）

stroke volume（SV）

cardiac output（CO）

cardiac index（CI） and left ventricle end-diastolic volume（LVEDV

P<0.05）.Compared with DDD group

the improvement of hemodynamic parameters was statistically significant in AAI group in CO

CI and LVEDV（P<0.05）.Conclusion The TCM syndrome manifestations and hemodynamics of SSS patients can be improved by pacemaker.AAI pacing is better than DDD pacing and VVI pacing in exerting the influence on the TCM syndrome manifestations of SSS by improving CO

CI and LVEDV.