Radboud Institute for Health Sciences, Department of Physiology, Radboud University Medical Center, Nijmegen, The Netherlands.
Radboud Institute for Health Sciences, Department of Cardiology, Radboud University Medical Center, Nijmegen, The Netherlands.
J Appl Physiol (1985). 2019 Aug 1;127(2):415-422. doi: 10.1152/japplphysiol.00190.2019. Epub 2019 Jun 27.
Aortic valve replacement (AVR) leads to remodeling of the left ventricle (LV). Adopting a novel technique to examine dynamic LV function, our study explored whether post-AVR changes in dynamic LV function and/or changes in aortic valve characteristics are associated with LV mass regression during follow-up. We retrospectively analyzed 30 participants with severe aortic stenosis who underwent standard transthoracic echocardiographic assessment before AVR [88 (IQR or interquartile range: 22-143) days], post-AVR [13 (6-22) days], and during follow-up [455 (226-907) days]. We assessed standard measures of LV structure, function, and aortic valve characteristics. Novel insight into dynamic LV function was provided through a four-chamber image by examination of the temporal relation between LV longitudinal strain (ε) and volume (ε-volume loops), representing the contribution of LV mechanics to volume change. AVR resulted in immediate changes in structural valve characteristics, alongside a reduced LV longitudinal peak ε and improved coherence between the diastolic and systolic part of the ε-volume loop (all < 0.05). Follow-up revealed a decrease in LV mass ( < 0.05) and improvements in LV ejection fraction and LV longitudinal peak ε ( < 0.05). A significant relationship was present between decline in LV mass during follow-up and post-AVR improvement in coherence of the ε-volume loops ( = 0.439, = 0.03), but not with post-AVR changes in aortic valve characteristics or LV function (all > 0.05). We found that post-AVR improvements in dynamic LV function are related to long-term remodeling of the LV. This highlights the potential importance of assessing dynamic LV function for cardiac adaptations in vivo. Combining temporal measures of left ventricular longitudinal strain and volume (strain-volume loop) provides novel insights in dynamic cardiac function. In patients with aortic stenosis who underwent aortic valve replacement, postsurgical changes in the strain-volume loop are associated with regression of left ventricular mass during follow-up. This provides novel insight into the relation between postsurgery changes in cardiac hemodynamics and long-term structural remodeling, but also supports the potential utility of the assessment of dynamic cardiac function.
主动脉瓣置换 (AVR) 可导致左心室 (LV) 的重塑。本研究采用一种新的技术来检查 LV 功能的动态变化，旨在探讨 AVR 后 LV 功能的变化和/或主动脉瓣特征的变化是否与随访期间 LV 质量的回归相关。我们回顾性分析了 30 名接受重度主动脉瓣狭窄的患者，他们在 AVR 前 [88（IQR 或四分位距：22-143）天]、AVR 后 [13（6-22）天] 和随访期间 [455（226-907）天] 进行了标准经胸超声心动图评估。我们评估了 LV 结构、功能和主动脉瓣特征的标准指标。通过检查 LV 纵向应变 (ε) 和体积 (ε-体积环) 之间的时间关系，提供了对 LV 功能动态的新见解，代表了 LV 力学对体积变化的贡献。AVR 导致结构瓣特征的即刻变化，同时 LV 纵向峰值 ε 降低，ε-体积环的舒张和收缩部分之间的一致性提高（均 < 0.05）。随访显示 LV 质量下降（ < 0.05），LV 射血分数和 LV 纵向峰值 ε 改善（均 < 0.05）。在随访期间 LV 质量下降与 AVR 后 ε-体积环一致性改善之间存在显著关系（ = 0.439， = 0.03），但与 AVR 后主动脉瓣特征或 LV 功能的变化无关（均 > 0.05）。我们发现，AVR 后 LV 功能的改善与 LV 的长期重塑有关。这强调了评估体内 LV 功能的心脏适应性的潜在重要性。结合 LV 纵向应变和体积的时间测量（应变-体积环）提供了对动态心脏功能的新见解。在接受主动脉瓣置换的主动脉瓣狭窄患者中，术后应变-体积环的变化与随访期间 LV 质量的回归相关。这为心脏血流动力学术后变化与长期结构重塑之间的关系提供了新的见解，但也支持评估动态心脏功能的潜在效用。
