Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, 7-5-2, Kusunoki-cho, Chuo-ku, Kobe, 650-0017, Japan.
Int J Cardiovasc Imaging. 2020 Jul;36(7):1203-1212. doi: 10.1007/s10554-020-01813-9. Epub 2020 Mar 18.
This study aimed to test the hypothesis that left ventricular dyssynchrony may negatively affect left atrial (LA) dyssynchrony and reservoir function, and cardiac resynchronization therapy (CRT) may improve LA function. It also assessed, whether residual LA dyssynchrony affects the prognosis in patients with heart failure with reduced ejection fraction (HFrEF). Ninety subjects were included: 40 HFrEF patients with a wide-QRS complex (≧130 ms), 28 HFrEF patients with a narrow-QRS, and 22 normal controls. LA global longitudinal strain (LA-GLS) and LA dyssynchrony were quantified by speckle-tracking strain analysis. LA dyssynchrony was defined as the maximal difference of time-to-peak strain (LA time-diff). All patients with a wide-QRS underwent CRT, and event-free survival was tracked for 24 months. At baseline, LA dyssynchrony was significantly more pronounced in patients with a wide-QRS HFrEF (342 ± 126 ms) than that in patients with a narrow-QRS (236 ± 127 ms, P < 0.001) and controls (186 ± 78 ms, P < 0.001). Six months after CRT, LA-GLS significantly improved from 11.9 ± 4.7 to 19.6 ± 10.1% (P < 0.05) and LA time-diff was reduced from 338 ± 123 to 245 ± 141 ms (P < 0.05) in responders only. Patients with an LA time-diff < 202 ms and those with an LA-GLS ≧14.6% six months after CRT showed significantly better outcomes than the others (P < 0.05, respectively). Among the responders, those with an LA time-diff < 202 ms after CRT showed a better prognosis than others (P < 0.05). CRT improved LA dyssynchrony and reservoir function through the improved left ventricular coordination. Reduced LA dyssynchrony and improved LA reservoir function after CRT lead to better outcomes.
这项研究旨在检验左心室不同步可能会对左心房（LA）不同步和储备功能产生负面影响，以及心脏再同步治疗（CRT）是否可以改善 LA 功能的假设。它还评估了残余 LA 不同步是否会影响射血分数降低的心力衰竭（HFrEF）患者的预后。共纳入 90 例受试者：40 例宽 QRS 综合波（≧130ms）的 HFrEF 患者、28 例窄 QRS 的 HFrEF 患者和 22 例正常对照者。采用斑点追踪应变分析量化 LA 整体纵向应变（LA-GLS）和 LA 不同步。LA 不同步定义为应变达峰时间的最大差异（LA 时间差）。所有宽 QRS 的患者均接受 CRT 治疗，并跟踪 24 个月的无事件生存情况。在基线时，宽 QRS 的 HFrEF 患者的 LA 不同步明显更严重（342±126ms），而窄 QRS 的 HFrEF 患者（236±127ms，P<0.001）和对照组（186±78ms，P<0.001）。CRT 治疗 6 个月后，LA-GLS 显著改善，从 11.9±4.7%增加到 19.6±10.1%（P<0.05），LA 时间差从 338±123ms 减少到 245±141ms（P<0.05），仅在应答者中。LA 时间差 <202ms 和 CRT 治疗后 6 个月 LA-GLS ≧14.6%的患者的结果明显优于其他患者（分别为 P<0.05）。在应答者中，CRT 治疗后 LA 时间差 <202ms 的患者预后优于其他患者（P<0.05）。CRT 通过改善左心室协调性来改善 LA 不同步和储备功能。CRT 后 LA 不同步减少和储备功能改善导致预后更好。
