Right ventricular outflow tract septal pacing versus apical pacing: A prospective, randomized, single-blind 5-years follow-up study of ventricular lead performance and safety / 华中科技大学学报（医学）（英德文版）

Lead placement for ventricular pacing variably impacts the physiological benefit of the patient. This study evaluated the ventricular lead performance and safety of right ventricular outflow tract septal pacing in patients with bradyarrhythmia in South China over 60-month follow-up. Totally, 192 patients (108 males, and 84 females, 63±21 years old) with bradyarrhythmia were randomly divided into two groups. The right ventricular outflow tract septum (RVOTs) group had lead placement near the septum (n=97), while the right ventricular apex (RVA) group had a traditional apical placement (n=95). RV septal lead positioning was achieved with a specialized stylet and confirmed using fluoroscopic projection. All patients were followed up for 60 months. Follow-up assessment included stimulation threshold, R-wave sensing, lead impedance and lead complications. The time of electrode implantation in both the ROVTs and RVA groups were significantly different (4.29±0.61 vs. 2.16±0.22 min; P=0.009). No differences were identified in threshold, impedance or R-wave sensing between the two groups at 1st, 12th, 36th and 60th month during the follow-up period. No occurrence of electrode displacement, increased pacing threshold or inadequate sensing was found. The long-term active fixation ventricular electrode performance in RVOTs group was similar to that in RVA group. RVOTs pacing near the septum using active fixation electrodes may provide stability during long-term follow-up period.

Effect of cardiac resynchronization therapy on cardiac function post A-V and V-V optimization / 中华心血管病杂志

<p><b>OBJECTIVE</b>To assess the effect of A-V, V-V delay optimization on cardiac function and clinical improvement in patients with refractory heart failure underwent cardiac resynchronization therapy (CRT).</p><p><b>METHOD</b>Thirty-two patients with chronic heart failure received CRT and cardiac function was measured at 7 days, 3 months and 6 months post CRT before and after A-V and V-V delay optimizations.</p><p><b>RESULTS</b>A-V delay optimization was initiated in 28, 10 and 6 cases at 7th day, 3rd month and 6th month after CRT. V-V delay optimization was performed in 29, 6 and 5 cases at 7th day, 3rd month and 6th month after CRT. Ts-SD, LVEF, VTI and E/Em were significantly improved after CRT compared to pre-CRT (P < 0.01, P < 0.05, P < 0.05, P < 0.05; respectively). Compared to pre-optimization, the indexes of ventricular synchronization were significantly improved (P < 0.05) while indexes of cardiac function remained unchanged post optimization at 7th day after CRT. The indexes of ventricular synchronization post optimization were similar at 7th, 3rd and 6th months after CRT (P > 0.05). LVEF and diastolic filling time were significantly increased after 6 months CRT post A-V, V-V delay optimization (P < 0.01).</p><p><b>CONCLUSION</b>A-V, V-V delay optimization at 7th day after CRT can significantly improve ventricular synchronization and is associated with further improved cardiac function 6 months after CRT.</p>