Background: Left ventricular (LV) global longitudinal strain (GLS) has emerged as a significant prognostic marker in patients after myocardial infarction (MI). Although elevated LV filling pressure after MI might alter GLS, direct evidence for this is lacking. This study aimed to clarify the association between GLS and LV filling pressure in a large animal MI model. Methods: A total of 104 Yorkshire pigs underwent both echocardiographic and hemodynamic assessments 1 to 4 weeks after induction of large anterior MI. GLS was measured in the apical four-chamber view using a semi-automated speckle-tracking software. LV pressure-volume relationship was invasively measured using a high-fidelity pressure-volume catheter. GLS >−14% was considered impaired. Results: Compared to pigs with LV ejection fraction (LVEF) >40% and preserved GLS (n=29), those with LVEF >40% and impaired GLS (n=37) and those with LVEF ≤40% (n=38) had significantly higher LV end-diastolic pressure (15.5±5.5 vs. 19.7±5.8 and 19.6±6.6 mmHg; P=0.008 and P=0.026, respectively) and higher LV mean diastolic pressure (7.1±2.9 vs. 10.4±4.5 and 11.1±5.4 mmHg; P=0.013 and P=0.002, respectively). GLS was modestly correlated with tau (r=0.21, P=0.039) and slope of LV end-diastolic pressure-volume relationship (r=0.43, P<0.001). Impaired GLS was associated with higher LV end-diastolic and mean diastolic pressures after adjusting for LVEF and baseline characteristics (P=0.026 and P=0.001, respectively). Conclusions: Impaired GLS assessed by speckle-tracking echocardiography was associated with elevated LV filling pressure after MI. GLS has an incremental diagnostic value for detecting elevated LV filling pressure and may be particularly useful for evaluating post-MI patients with preserved LVEF.

中文翻译：

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左心室整体纵向应变受损与心肌梗死后左心室充盈压升高有关

背景：左心室 (LV) 整体纵向应变 (GLS) 已成为心肌梗死 (MI) 后患者的重要预后标志物。尽管 MI 后 LV 充盈压升高可能会改变 GLS，但缺乏这方面的直接证据。本研究旨在阐明大型动物 MI 模型中 GLS 与 LV 充盈压之间的关联。方法：在诱导大前壁心肌梗死后 1 至 4 周，共有 104 头约克夏猪接受了超声心动图和血流动力学评估。使用半自动散斑跟踪软件在心尖四腔视图中测量 GLS。使用高保真压力-容积导管有创地测量 LV 压力-容积关系。GLS >-14% 被认为是受损的。结果：与 LV 射血分数 (LVEF) > 40% 和保留 GLS 的猪（n = 29）相比，LVEF > 40% 且 GLS 受损的患者 (n=37) 和 LVEF ≤40% 的患者 (n=38) 的 LV 舒张末期压力显着升高（15.5±5.5 与 19.7±5.8 和 19.6±6.6 mmHg；P =0.008 和 P=0.026）和更高的 LV 平均舒张压（7.1±2.9 与 10.4±4.5 和 11.1±5.4 mmHg；分别为 P=0.013 和 P=0.002）。GLS 与 tau (r=0.21, P=0.039) 和 LV 舒张末期压力-容积关系的斜率 (r=0.43, P<0.001) 适度相关。在调整 LVEF 和基线特征后，受损的 GLS 与较高的 LV 舒张末期和平均舒张压相关（分别为 P=0.026 和 P=0.001）。结论：通过斑点追踪超声心动图评估的受损 GLS 与 MI 后 LV 充盈压升高有关。