The Analysis Of The Relationship Between The Width Of The QRS Complex And The Position And The Intensity Of The Stimulus In Ventricle

Objective: To our knowledge, the QRS complex duration can, in some given occasions, be a index of the cardiac function, responding the biventricle synchronism. The narrower the QRS complex duration is, the time of the ventricular activation is, with the more possibility of the cardiac synchronism. The data makes clear, with a broader QRS complex duration, the sequence of ventricular activation becomes abnormal, while the synchronism of the myocardium losing. Some research have been indicated that to the patients after the implantation of the cardiac pacemaker, the position of the ventricular electrode can effect the width and the morphology of the QRS complex, and ultimately change the hemodynamics and the cardiac function, even remold the myocardium and eventually cause atrial fibrillation and other arrhythmias. In our research, we investigate the relationship between the width of the QRS complex and the position and the intensity of the stimulus in ventricle, discuss the differences of the cardiac synchronism under different pacing with a special position and the intensity, and then direct the location of the ventricular electrode in the pacemaker implantation.Method:1 Object: 28 patients who were under the radiofrequency catheter ablation(RFCA) treatment of left-sided pathway(13 males, 15 females), aged 17 to 66, were enrolled into this study between March 2014 and February 2015 at the Second Hospital of Hebei Medical University. After the pathway was ablated, we stimulated the different parts(high, middle, low of the right ventricular outflow tract septum; Left/Right ventricular apex; his-bundle /para-hisian area) of the ventricle with different intensity(3V, 5V, 7V), and made the ECG while stimulating, then we analyzed the width of the QRS complex.2 Statistical analysis: Statistical analysis was conducted with SPSS 16.0 software. The quantitative data were represented as mean±SD. The qualitative data were represented as a percentage. The quantitative data was checked using analysis of variance. The level of significance was set at 0.05.Results:1 In the same position, there is no significant difference to the QRS complex durations among the different stimulus intensity groups( F=1.297,P=0.274>0.05). We can find statistics differences among the groups with the different pacing positions while stimulating in the same intensity(F=120.198,P=0.000<0.05). There is no interaction effect between the stimulus position and intensity(F=0.423,P=0.936>0.05).2 There is no significant differences to the QRS complex duration among the different stimulus intensity groups in the same position. Except low, high of the right ventricular outflow tract septum and left ventricular apex group, there is significant difference between every two groups to the QRS complex duration.3 In His-bundle/para-hisian area, the QRS complex duration is the narrowest, which is narrower than the middle of septum, while in the right ventricular apex area, the QRS complex duration is the broadest and is not a physiological pacing.Conclusion:1 In the same position of the ventricle, there is no statistics difference to the width of the QRS complex while stimulating in different intensity.2 While stimulating the ventricle in the same intensity, there is significant difference to the width of the QRS complex in the different position. Hisian area is the narrowest, and the middle septum is the narrower one. The QRS complex is the widest in right ventricular apex.3 In the implantation of the cardiac pacemakers, His-bundle/para-hisian area can be the best position of the ventricular electrode because of the physiological pacing, and the middle of right ventricular outflow tract septum can be also a more physiological pacing position than all other positions, the right ventricular apex is the unphysiological pacing position as a result of the significant delayed ventricle stimulation.