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.

Reduction of atrial fibrillation in remotely monitored pacemaker patients: results from a Chinese multicentre registry / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Many recipients of implantable cardiac electronic devices have atrial fibrillation (AF) occurrences after device implantation, even if there is no previous history of AF, and some of the episodes are asymptomatic. The purpose of this study was to evaluate trends in AF burden following early AF detection in patients treated with pacemakers equipped with automatic, daily Home Monitoring function.</p><p><b>METHODS</b>Between February 2009 and December 2010, the registry recruited 701 pacemaker patients (628 dual-chamber, 73 biventricular devices) at 97 clinical centers in China. Daily Home Monitoring data transmissions were analyzed to screen for the AF burden. In-office follow-ups were scheduled for 3 and 6 months after implantation. Upon first AF (i.e., mode-switch) detection in a patient, screening of AF burden by Home Monitoring was extended for the next 180 days.</p><p><b>RESULTS</b>At least one episode of AF was observed in 22.9% of patients with dual-chamber pacemakers and in 28.8% of patients with biventricular pacemakers. The first AF detection in a patient occurred, on average, about 2 months before scheduled follow-up visits. In both pacemaker groups, mean AF burden decreased significantly (P < 0.05) over 180 days following first AF detection: from 12.0% to 2.5% in dual-chamber and from 12.2% to 0.5% in biventricular pacemaker recipients. The number of patients with an AF burden >10% per month was significantly reduced over 6 months of implantation in both dual chamber (38 patients in the first month vs. 21 patients in month 6, P < 0.05) and biventricular (7 patients in the first month vs. 0 patient in months 4-6, P < 0.05) pacemaker recipients.</p><p><b>CONCLUSIONS</b>Automatic, daily Home Monitoring of patients treated with cardiac pacemakers allows early detection of AF, and there is a gradual and significant decrease in AF burden.</p>

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>