Left ventricular mechanical dispersion predicts arrhythmic risk in mitral valve prolapse
Left ventricular mechanical dispersion predicts arrhythmic risk in mitral valve prolapse
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DOI：
10.1136/heartjnl-2018-314269
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发表时间：
2019-07-01
期刊：
影响因子：
5.7
通讯作者：
Delling, Francesca N.
中科院分区：
文献类型：
--
作者：
Ermakov, Simon;Gulhar, Radhika;Delling, Francesca N.
目的双叶二尖瓣脱垂（MVP）合并局灶性或弥漫性心肌纤维化与室性心律失常和/或心脏骤停有关。斑点追踪超声心动图（STE）测量的左心室（LV）机械离散度是测量先前与心肌纤维化相关的心室收缩异质性的指标。本研究的目的是确定机械分散是否可以识别MVP在较高的mathermic risk.Methods我们确定了32个连续的mathermic MVP（A-MVP）的历史复杂的心室异位霍尔特/事件监测（n=23）或除颤器放置（n=9）沿着与27 MVP没有mathermic并发症（NA-MVP）和39个控制。STE计算18节段左室模型的平均峰值纵向应变（GLS）和各节段达到峰值应变时间的标准差（SD）（52 vs 42 ms，p=0.005），尽管LV射血分数（62% vs 63%，p=0.42）和GLS（-19.7 vs-21，p=0.045）相似。A-MVP和NA-MVP具有相似的人口统计学、LV射血分数和GLS（均p> 0.05）。A-MVP的双叶脱垂更多（69% vs 44%，p=0.031），二尖瓣返流程度相似（两组大多为微量或轻度）（p> 0.05）。与NA-MVP相比，A-MVP表现出更大的机械分散（59 vs 43 ms，p=0.0002）。多因素分析显示，机械弥散度是预测MVP患者预后的唯一重要指标（OR 1.1，95% CI 1.02 ~ 1.11，p=0.006）。
Objective Bileaflet mitral valve prolapse (MVP) with either focal or diffuse myocardial fibrosis has been linked to ventricular arrhythmia and/or sudden cardiac arrest. Left ventricular (LV) mechanical dispersion by speckle-tracking echocardiography (STE) is a measure of heterogeneity of ventricular contraction previously associated with myocardial fibrosis. The aim of this study is to determine whether mechanical dispersion can identify MVP at higher arrhythmic risk.Methods We identified 32 consecutive arrhythmic MVPs (A-MVP) with a history of complex ventricular ectopy on Holter/event monitor (n=23) or defibrillator placement (n=9) along with 27 MVPs without arrhythmic complications (NA-MVP) and 39 controls. STE was performed to calculate global longitudinal strain (GLS) as the average peak longitudinal strain from an 18-segment LV model and mechanical dispersion as the SD of the time to peak strain of each segment.Results MVPs had significantly higher mechanical dispersion compared with controls (52 vs 42 ms, p=0.005) despite similar LV ejection fraction (62% vs 63%, p=0.42) and GLS (-19.7 vs -21, p=0.045). A-MVP and NA-MVP had similar demographics, LV ejection fraction and GLS (all p> 0.05). A-MVP had more bileaflet prolapse (69% vs 44%, p=0.031) with a similar degree of mitral regurgitation (mostly trace or mild in both groups) (p> 0.05). A-MVP exhibited greater mechanical dispersion when compared with NA-MVP (59 vs 43 ms, p=0.0002). Mechanical dispersion was the only significant predictor of arrhythmic risk on multivariate analysis (OR 1.1, 95% CI 1.02 to 1.11, p=0.006).Conclusions STE-derived mechanical dispersion may help identify MVP patients at higher arrhythmic risk.