Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
JACC Cardiovasc Imaging. 2013 Jun;6(6):704-13. doi: 10.1016/j.jcmg.2013.04.004.
Echocardiographic particle imaging velocimetry allows blood flow visualization and characterization of diastolic vortex formation that may play a key role in filling efficiency. We hypothesized that abrupt withdrawal of cardiac resynchronization therapy (CRT) would alter the timing of left ventricular diastolic vortex formation and modify cardiac time intervals. In patients with heart failure (HF) who had chronically implanted CRT devices, the timing of the onset of the diastolic vortex (TDV) from mitral valve opening, transmitral flow, and cardiac time intervals was measured at baseline and after deactivation and reactivation of CRT. Compared with control patients with cardiovascular risk factors but structurally normal hearts, TDV was significantly delayed in patients with HF. Deactivation of CRT resulted in striking delay in TDV due to disorganized flow and reduced flow acceleration, and reactivation reversed these characteristics instantly. In addition, CRT deactivation also prolonged the isovolumic contraction interval, which closely correlated with the changes in the TDV. These data suggest that CRT plays an important role in optimization of left ventricular diastolic filling.
超声心动图粒子成像测速技术可用于可视化血流并分析舒张期涡流的形成，后者可能在充盈效率中起关键作用。我们假设，突然停止心脏再同步治疗（CRT）会改变左心室舒张期涡流形成的时间，并改变心脏时间间隔。在长期植入 CRT 设备的心力衰竭（HF）患者中，在 CRT 停用和再激活时，从二尖瓣开口、经二尖瓣血流和心脏时间间隔测量舒张期涡流（TDV）的起始时间。与具有心血管危险因素但心脏结构正常的对照患者相比，HF 患者的 TDV 明显延迟。CRT 停用导致由于血流紊乱和血流加速减少而导致 TDV 明显延迟，而重新激活则立即逆转了这些特征。此外，CRT 停用还延长了等容收缩间隔，这与 TDV 的变化密切相关。这些数据表明，CRT 在优化左心室舒张充盈中起重要作用。
