College of Nursing and Health Innovation, University of Texas at Arlington, Arlington, TX, USA.
Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
J Cardiovasc Magn Reson. 2023 Oct 2;25(1):55. doi: 10.1186/s12968-023-00969-2.
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 (EF), when compared to gold-standard volumetric assessment (EF: r = 0.94, P < 0.0001). Likewise, integrating circumferential and longitudinal strain rate provided a close approximation of peak ejection and peak filling rates (PER and PFR, respectively) compared to their gold-standard volume-time equivalents (PER, r = 0.73, P < 0.0001 and PFR, 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 EF, PER, and PFR compared to all other groups, and HFpEF having less favorable EF and PFR 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.
左心室（LV）环向和纵向应变提供了对 LV 力学和功能的重要见解，它们各自有助于整个心动周期中的容积变化。我们试图通过数学上整合环向和纵向应变和应变速率来更详细地探索这种应变-容积关系，以预测 LV 容积和容积变化率。
从 Alberta HEART 研究的 229 名参与者（46 名健康对照者、77 名心力衰竭风险患者、70 名射血分数保留心力衰竭患者和 36 名射血分数降低心力衰竭患者）的心脏磁共振（CMR）图像中评估了左心室容积。LV 容积通过圆盘法评估，应变/应变速率通过 CMR 特征追踪法评估。
与金标准容积评估相比，整合心内膜环向和纵向应变非常接近 LV 射血分数（EF）（EF：r=0.94，P<0.0001）。同样，整合环向和纵向应变速率非常接近峰值射血和峰值充盈率（PER 和 PFR）与它们的金标准容积时间等效物（PER，r=0.73，P<0.0001 和 PFR，r=0.78，P<0.0001，分别）。此外，每个整合应变测量值都可以区分心力衰竭连续体中的患者（所有 P<0.01），与其他所有组相比，射血分数降低心力衰竭组的 EF、PER 和 PFR 更差，射血分数保留心力衰竭组的 EF 和 PFR 比风险和对照组都差。
本文的数据为在整个心动周期中将离散应变分量整合到容积测量中建立了理论框架，并强调了这种方法在区分心力衰竭连续体中患者的潜在益处。
