Left ventricular (LV) circumferential and longitudinal strain provide important insight into LV mechanics and function, each contributing to volumetric changes throughout the cardiac cycle. We sought to explore this strain-volume relationship in more detail, by mathematically integrating circumferential and longitudinal strain and strain rate to predict LV volume and volumetric rates of change. Cardiac magnetic resonance (CMR) imaging from 229 participants from the Alberta HEART Study (46 healthy controls, 77 individuals at risk for developing heart failure [HF], 70 patients with diagnosed HF with preserved ejection fraction [HFpEF], and 36 patients with diagnosed HF with reduced ejection fraction [HFrEF]) were evaluated. LV volume was assessed by the method of disks and strain/strain rate were assessed by CMR feature tracking. Integrating endocardial circumferential and longitudinal strain provided a close approximation of LV ejection fraction (EFStrain), when compared to gold-standard volumetric assessment (EFVolume: r = 0.94, P < 0.0001). Likewise, integrating circumferential and longitudinal strain rate provided a close approximation of peak ejection and peak filling rates (PERStrain and PFRStrain, respectively) compared to their gold-standard volume-time equivalents (PERVolume, r = 0.73, P < 0.0001 and PFRVolume, r = 0.78, P < 0.0001, respectively). Moreover, each integrated strain measure differentiated patients across the HF continuum (all P < 0.01), with the HFrEF group having worse EFStrain, PERStrain, and PFRStrain compared to all other groups, and HFpEF having less favorable EFStrain and PFRStrain compared to both at-risk and control groups. The data herein establish the theoretical framework for integrating discrete strain components into volumetric measurements across the cardiac cycle, and highlight the potential benefit of this approach for differentiating patients along the heart failure continuum.

中文翻译：

---

纵向和周向应变的整合可预测整个心动周期的体积变化，并沿心力衰竭连续体区分患者

左心室 (LV) 周向应变和纵向应变为了解 LV 力学和功能提供了重要的见解，每种应变都会导致整个心动周期的体积变化。我们试图通过数学整合周向和纵向应变以及应变率来预测左心室体积和体积变化率，更详细地探索这种应变-体积关系。来自艾伯塔省 HEART 研究的 229 名参与者的心脏磁共振 (CMR) 成像（46 名健康对照者、77 名有发生心力衰竭 [HF] 风险的个体、70 名射血分数保留的 HF 诊断患者和 36 名诊断为心力衰竭的患者）评估了射血分数降低的 HF [HFrEF]）。通过圆盘法评估左心室体积，并通过 CMR 特征跟踪评估应变/应变率。与金标准容量评估（EFVolume：r = 0.94，P < 0.0001）相比，整合心内膜周向和纵向应变可提供左室射血分数（EFStrain）的近似值。同样，与金标准体积-时间等效值（PERVolume，r = 0.73，P < 0.0001 和 PFRVolume，r = 0.78，P < 0.0001，分别）。此外，每个综合应变测量在 HF 连续体中区分患者（所有 P < 0.01），与所有其他组相比，HFrEF 组的 EFStrain、PERStrain 和 PFRStrain 较差，而 HFpEF 组的 EFStrain 和 PFRStrain 与两组相比较差。风险组和控制组。本文的数据建立了将离散应变分量整合到整个心动周期的体积测量中的理论框架，并强调了这种方法对于区分心力衰竭连续体患者的潜在好处。