Objective To compare the effects of right ventricular outflow pacing and right ventricular apex pacing on cardiac function.Methods Forty patients with DDD pacemaker implantation were randomly divided into right ventricular outflow pacing group and right ventricular apex pacing group depending on the position of ventricular lead.The QRS durations after operation were compared between the two groups.The left ventricular end diastolic diameter（LVEDD）,left ventricular ejection fraction（LVEF）,and left atrial diameter（LAD）were compared before and after operations.Results There was no significant difference in LVEDD,LVEF,and LAD by echocardiography between the two groups before operation.After operation the QRS duration of right ventricular apex pacing was significantly longer than that of right ventricular outflow pacing.After three months and six months follow-up,the LVEDD,LVEF,and LAD between the two groups were not significantly changed,but in the right ventricular apex pacing group there was a decreased tendency in LVEF.Conclusion The QRS duration was shorter in the right ventricular outflow pacing than that in the right ventricular apex pacing.However,there was not significant difference between the two groups.
Right ventricular outflow pacing
Right ventricular apex pacing
Left ventricular end diastolic diameter
Left ventricular ejection fraction