Lee Ki Hong, Cho Jeong Gwan, Park Hyung Wook, Yoon Nam Sik, Kim Sung Soo, Kim Mi Ran, Kim Min Chul, Cho Kyung Hoon, Kim Hyun Kuk, Kim Cheol Hwan, Kim Kyung Hwan, Jun Seung Jin, Kim Woo Jin, Lee Kyoung Jin, Jeong Hae Chang, Cho Jae Yeong, Park Keun-Ho, Sim Doo sun, Yoon Hyun Ju, Kim Kye Hun, Hong Young Joon, Kim Ju Han, Ahn Youngkeun, Jeong Myung Ho, Park Jong Chun
Chonnam National University Hospital, Gwangju, South Korea.
Chonnam National University Hospital, Gwangju, South Korea.
Int J Cardiol. 2014 Oct 20;176(3):962-8. doi: 10.1016/j.ijcard.2014.08.131. Epub 2014 Aug 27.
Mechanical dyssynchrony (MD) is associated with poor outcomes in many different populations. However, the predictors for the development of MD after chronic right ventricular (RV) pacing are not well known.
Pacing QRS morphology and MD using echocardiography was analyzed in 175 consecutive patients that have pacemaker implantation during a 7.6 year median follow-up. Predictive score for MD was constructed using QRS morphology variables and calculated by summing the points of the 4 variables: duration (≥150 ms, 1 point), transition (1 point), notching (2 points), and left-axis deviation (1 point), based on a multivariate-adjusted risk relationship with MD.
Sixty-eight (38.9%) patients developed MD. Patients with MD had worsened left ventricular systolic function (ejection fraction from 64.6±10.6% to 59.1±10.4%, p<0.001) and heart failure symptoms (New York Heart Association functional class increase from 1.1±0.3 to 1.9±0.8, p<0.001). In an electrocardiographic analysis, QRS duration≥150 ms, the presence of precordial axis transition, notching, and left-axis deviation were strongly associated with MD. Predictive score for MD using QRS morphology parameters displayed an excellent graded relationship with MD (score 0: 3.4% vs. 1: 12.5% vs. 2: 22.6% vs. 3: 45.0% vs. 4: 57.9% vs. 5: 72.7%, linear p<0.001) (model performance c-static 0.78, 95% confidence interval 0.72-0.85, p<0.001).
Patients with MD experienced a decline in left ventricular systolic function and an increase in heart failure symptoms after chronic RV pacing. A new scoring system using QRS morphology is considered a simple and efficient tool for predicting the development of MD after chronic RV pacing.
机械性不同步（MD）在许多不同人群中都与不良预后相关。然而，慢性右心室（RV）起搏后MD发生的预测因素尚不清楚。
对175例连续接受起搏器植入的患者进行了中位7.6年随访，分析其起搏QRS形态及利用超声心动图检测的MD情况。基于与MD的多变量调整风险关系，使用QRS形态变量构建MD预测评分，通过对4个变量的得分求和来计算：时限（≥150 ms，1分）、移行（1分）、切迹（2分）和左轴偏移（1分）。
68例（38.9%）患者发生MD。发生MD的患者左心室收缩功能恶化（射血分数从64.6±10.6%降至59.1±10.4%，p<0.001），心力衰竭症状加重（纽约心脏协会心功能分级从1.1±0.3升至1.9±0.8，p<0.001）。在心电图分析中，QRS时限≥150 ms、胸前导联轴移行、切迹及左轴偏移与MD密切相关。使用QRS形态参数的MD预测评分与MD呈现出良好的分级关系（评分0：3.4% vs. 1：12.5% vs. 2：22.6% vs. 3：45.0% vs. 4：57.9% vs. 5：72.7%，线性p<0.001）（模型性能c统计量0.78，95%置信区间0.72 - 0.85，p<0.001）。
慢性RV起搏后发生MD的患者左心室收缩功能下降，心力衰竭症状增加。一种使用QRS形态的新评分系统被认为是预测慢性RV起搏后MD发生的简单有效工具。
