长期右心室心尖部起搏对心室重构的影响

目的探讨长期右心室心尖部（RVA）起搏对心室重构的影响。方法回顾性分析1997年6月至1998年11月，92例因病态窦房结综合征首次植入双腔起搏器的患者。对照组共有45例患者入选。起搏器植入术前行12导联心电图和超声心动图检查，术后随访时记录未起搏的心电图和超声心动图。结果传统双腔起搏组患者平均心室累积起搏比例为（90．1±4．0）％，平均随访时间为（3．3±0．5）年。起搏组患者自身QRS时限由术前（874-9）ms增加到随访时的（94±10）ms（P〈0．001）。左心室舒张末内径（LVEDD）由（464-3）mm增加到（50±4）mm（P〈0．001），左心室射血分数（LVEF）由0．63±0．04降低到0．57±0．05（P〈0．001）。Logistic回归分析显示，起搏器植入时老龄（〉65岁）（OR3．41，95％CI1．07～10．90，P=0．04）、长期RVA起搏（OR3．91，95％CI1．10～13．89，P=0．03）和冠心病史（OR7．33，95％CI1．09～50．29，P=0．04）是QRS时限增宽（〉7ms）的独立预测因素。对照组各指标随访前后差异无统计学意义。结论长期RVA起搏可能引起自身QRS时限增宽，提示RVA起搏引起心脏特殊传导系统和／或心室肌传导功能损害。起搏器植入时老龄、RVA起搏和冠心病史是自身QRS时限增宽的独立预测因子。

Prolonged native QRS duration as an evidence of electrical remodeling after right ventricular pacing in the human heart

Objective Mechanical remodeling of the ventricles with chronic right ventricular apical (RVA) pacing has been demonstrated in patients with sinus node dysfunction. However, the potential of RVA pacing to induce electrical remodeling of the ventricles has not been carefully investigated. Methods Ninty-two patients with sinus node dysfunction(mean age: 68.4y; 47 men) who underwent initial pacemaker implanta-tion, were selected for the study. During routine device clinic visits, an unpaced electrocardiogram (ECG) and echocardiogram were recorded. The matched-control group consisted of 45 patients. Results The mean follow-up time was(3.3±0.5)years and the mean Cum% VP was (90.1±4.0)% in patients with device implanta-tion. The intrinsic QRS duration prior to device implantation was(87±9) ms, and increased to(94±10) ms (P<0.001) at last follow-up visit. Chronic RVA pacing also resulted in an increase in left ventricular end-di-astolic diameter (LVEDD) from(46±3)to(50±4) mm (P<0.001), and a decrease of left ventricular ejec-tion fraction(LVEF) from 0.63±0.04 to 0.57±0.05 mm(P<0.001). None of these changes was observed among the control group. Logistic regression analysis revealed that older age at the time of pacemaker implanta-tion (OR 3.41, 95% CI 1.07～10.90,P =0.04), chronic RVA pacing (OR 3.91,95% CI 1.10～13.89, P = 0.03), and coronary artery disease (CAD) (OR 7.33, 95% CI 1.09～50.29, P= 0.04) were independ-ent predictors of the prolongation of intrinsic QRS duration. Conclusions This study indicates that chronic RVA pacing may lead to a prolongation of intrinsic QRS duration. Elderly age, chronic RVA pacing, and the presence of CAD independently predict the changes of QRS duration.