右室不同部位起搏对二尖瓣功能的影响

目的比较右室心尖部（RVA）起搏与右室流出道间隔部（RVOT）起搏对二尖瓣功能的影响，探讨间隔部起搏的临床益处。方法选取因Ⅲ度或高度房室传导阻滞植入起搏器患者72例，随机分成RVA组40例和RVOT组32例，观察两组术前及术后6个月左室射血分数（LVEF）、左室舒张末期内径（LVDd）以及二尖瓣功能变化。结果术后6个月，RVA组LVEF较术前明显降低，而RVOT组与术前相比无明显变化，两组LVDd与术前相比均无明显变化。RVA组新发反流及反流加重比率较RVOT组明显增加。结论与RVA起搏相比，RVOT起搏对二尖瓣功能及左室功能影响较小，是安全有效的起搏部位。

Effect of different right ventricular pacing sites on mitral valve function

Objective To assess the effect of different right ventricular pacing sites on mitral valve function. Methods Seventy - two patients with complete or high - degree atrioventricular block were randomized into right ventricular apex pacing （RVA） group （ n = 40） and right ventricular outflow tract septum pacing（RVOT） group （n = 32）. The changes in ejection fraction, left ventricular diastolic diameter（LVDd） and mitral valve function during followup were evaluated by echocardiography. Resuits Six months after implantation of pacemakers, ejection fraction were decreased in RVA group, while unchanged in RVOT group, ejection fraction and LVDd were unchanged in both groups. The rate of new and worsened mitral valve regurgitation in RVA group was increased compared with patients in RVOT group. Conclusions Compared with RVA pacing, RVOT pacing have little negative effect on mitral valve function and left ventrieular function, is a safe and effective pacing site.