A Hemodynamic Study In Patients With Right Ventricular Septal Pacing

Objective:To compare the hemodynamic changes of right ventricular septal pacing with effect of traditional right ventricular apical pacing;to explore the clinical feasibility and safety of the technique that doctors implant screw-in transvenous pacing lead in right ventricular septum;on the basis of positive results, to discuss the mechanism of hemodynamic improvement of right ventricular septal pacing.Methods:There were 10 patients who need receive permanent pacing, five of them with atrioventricular block and five of them with sick sinus syndrome, 6 male and 4 female, the mean age was 63.50 ± 10.83 years old;six of them were in normal heart function, three were in NYHA class Ⅰ, one was class Ⅱ. All of them used VVI pacing mode .We examined hemodynamics by ultrasonic cardiogram (UCG) and recorded surface electrocardiogram (ECG) before implantation. To research the hemodynamic difference betweeen right ventricular septal pacing and right ventricular apical pacing by , auto-control and group-control means. There were two steps for our reserch during pacemaker implantation. Firstly, we fixed screw-in pacing leads at right ventricular apex(RVA), about fifteen minutes later we determined pacing threshold and adjusted pacing rates to obtain all captured rhythm,then examined UCG and ECG;Secondly, we moved screw-in pacing leads form RVA to right ventricular septum(RVS) under X-ray and ECG suggestion, the last procedure was same as the first step. On 3-5 days after operation, we repeated UCG and ECG examination to evaluate changes of hemodymics. All the RVS patients were investigated for 6 months after surgery. We examined their UCG and ECG. They were compared with another group patients who received RVA . pacing in order to evaluate the long-term hemodynamic changes.Results: Comparing the hemodynamic changes of right ventricular septal pacing with right ventricular apical pacing, we found the hemodynamic parameters such as LVEF, FS, SV and EV during RVS pacing were significantly better than parameters during RVA pacing(P<0.05). In contrast to RVA pacing, the QRS duration of RVS pacing was significantly narrowed (PO.001), the axis and QRS complex of ECG during RVS pacing more get close intrinsic level which had normal ventricular activation sequence and biventricular contraction synchrony. Investigation for mean time of six months after surgery indicated that RVS pacing were significantly better than RVA pacing in hemodynamicsCPO.OS).Conclusion: The primary study results suggest: 1. It's feasible and safe to use screw-in leads for RVS pacing. 2. The hemodynamic parameters during RVA pacing were significantly worse than preoperative parameters. And no significant difference existed between RVS pacing and intrinsic rhythm. 3. The hemodynamic parameters of RVS pacing were significantly better than that of RVA pacing, so can avoid or relieve deterioration of cardiac function by traditional RVA pacing. 4. RVS pacing could improve hemodynamic effect through keeping normal ventricular activation sequence and biventricular contraction synchrony.