长QT综合征中心肌收缩的跨壁差异:离子通道功能障碍的机械后果
Kristina Hermann Haugaa1, Jan P Amlie, Knut Erik Berge
1Department of Cardiology, Oslo University Hospital, Oslo, Norway.
Circulation
|September 22, 2010
概括
长QT综合征 (LQTS) 患者表现出长时间的心肌收缩,特别是在心下内脏. 这种横向性机械分散与症状LQTS个体的心律失常风险有关.
科学领域:
- 心脏病学 心脏病学
- 心脏电生理学 心脏电生理学
- 心声回声扫描 (Echocardiography) 是一种心声回声扫描.
背景情况:
- 长QT综合征 (LQTS) 是一种以心肌动作潜力的持续时间延长为特征的疾病.
- 这种延长在心脏内膜和心脏中部最明显.
- 长时间的动力潜能持续时间可能导致心脏收缩时间延长,通过应变回声心脏图检测到.
研究的目的:
- 为了调查心肌收缩是否在LQTS患者的心下肌纤维中最长时间.
- 为了确定不均的超收缩是否与LQTS中自发性心律失常的风险相关.
主要方法:
- 应变心力回声学用于评估心肌收缩时间在16个左心室 (LV) 段.
- 收缩持续时间是从心电图Q波到峰值应变的时间.
- 在纵向轴 (心下纤维) 和周围轴 (心中纤维) 上分析了应变.
主要成果:
- 在LQTS突变携带者 (445±45毫秒) 中,平均收缩时间明显长于健康个体 (390±40毫秒).
- 与无症状携带者 (425 ± 45 ms) 相比,有症状的LQTS携带者表现出更长的收缩时间 (460 ± 40 ms).
- 在有症状的LQTS患者中,纵向应变持续时间超过周围应变持续时间 (460 ± 45毫秒对比445 ± 45毫秒),表明跨壁机械分散.
结论:
- 具有症状的LQTS突变携带者表现出延长的下内心和心肌收缩时间.
- 这种超神经机械分散表明症状LQTS的心脏机械发生了变化.
- 在无症状的LQTS患者或健康个体中没有观察到跨体外机械分散.
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