Institute for Surgical Research, Oslo University Hospital, Oslo, Norway.
Center for Cardiological Innovation, Oslo University Hospital, Oslo, Norway.
Eur Heart J Cardiovasc Imaging. 2020 Feb 1;21(2):143-153. doi: 10.1093/ehjci/jez231.
Regional myocardial work may be assessed by pressure-strain analysis using a non-invasive estimate of left ventricular pressure (LVP). Strain by speckle tracking echocardiography (STE) is not always accessible due to poor image quality. This study investigated the estimation of regional myocardial work from strain by feature tracking (FT) cardiac magnetic resonance (CMR) and non-invasive LVP.
Thirty-seven heart failure patients with reduced ejection fraction, left bundle branch block (LBBB), and no myocardial scar were compared to nine controls without LBBB. Circumferential strain was measured by FT-CMR in a mid-ventricular short-axis cine view, and longitudinal strain by STE. Segmental work was calculated by pressure-strain analysis. Twenty-five patients underwent 18F-fluorodeoxyglucose (FDG) positron emission tomography. Segmental values were reported as percentages of the segment with maximum myocardial FDG uptake. In LBBB patients, net CMR-derived work was 51 ± 537 (mean ± standard deviation) in septum vs. 1978 ± 1084 mmHg·% in the left ventricular (LV) lateral wall (P < 0.001). In controls, however, there was homogeneous work distribution with similar values in septum and the LV lateral wall (non-significant). Reproducibility was good. Segmental CMR-derived work correlated with segmental STE-derived work and with segmental FDG uptake (average r = 0.71 and 0.80, respectively).
FT-CMR in combination with non-invasive LVP demonstrated markedly reduced work in septum compared to the LV lateral wall in patients with LBBB. Work distribution correlated with STE-derived work and energy demand as reflected in FDG uptake. These results suggest that FT-CMR in combination with non-invasive LVP is a relevant clinical tool to measure regional myocardial work.
通过使用左心室压力（LVP）的无创估计值，压力-应变分析可用于评估局部心肌做功。由于图像质量差，斑点追踪超声心动图（STE）的应变并不总是可获得。本研究旨在通过特征追踪（FT）心脏磁共振（CMR）和无创 LVP 来估计局部心肌做功。
将 37 例射血分数降低、左束支传导阻滞（LBBB）且无心肌瘢痕的心力衰竭患者与 9 例无 LBBB 的对照组进行比较。通过 FT-CMR 在中室短轴电影视图中测量周向应变，并通过 STE 测量纵向应变。通过压力-应变分析计算节段功。25 例患者接受 18F-氟脱氧葡萄糖（FDG）正电子发射断层扫描。节段值报告为具有最大心肌 FDG 摄取的节段的百分比。在 LBBB 患者中，净 CMR 衍生的功在间隔部为 51±537（平均值±标准偏差），而在左心室（LV）侧壁为 1978±1084mmHg·%（P<0.001）。然而，在对照组中，工作分布均匀，间隔部和 LV 侧壁的工作值相似（无显著性差异）。可重复性良好。节段性 CMR 衍生的工作与节段性 STE 衍生的工作和节段性 FDG 摄取相关（平均 r 值分别为 0.71 和 0.80）。
与 LBBB 患者的 LV 侧壁相比，FT-CMR 与无创 LVP 相结合可明显降低间隔部的工作。工作分布与 STE 衍生的工作以及 FDG 摄取所反映的能量需求相关。这些结果表明，FT-CMR 与无创 LVP 相结合是一种用于测量局部心肌做功的相关临床工具。
