Diaz-Navarro Rienzi A, Kerkhof Peter L M
Department of Internal Medicine and Center for Biomedical Research, School of Medicine, Universidad de Valparaiso, Valparaiso, Chile.
Department of Radiology & Nuclear Medicine, Amsterdam University Medical Centers, Amsterdam, Netherlands.
Front Cardiovasc Med. 2021 Aug 30;8:695883. doi: 10.3389/fcvm.2021.695883. eCollection 2021.
Left ventricular (LV) global function index (LVGFI) has been introduced as a volume-based composite metric for evaluation of ventricular function. The definition formula combines stroke volume (SV), end-systolic volume (ESV), end-diastolic volume (EDV) and LV mass/density. Being a dimensionless ratio, this new metric has serious limitations which require evaluation at a mathematical and clinical level. Using CMRI in 96 patients we studied LV volumes, various derived metrics and global longitudinal strain (GLS) in order to further characterize LVGFI in three diagnostic groups: acute myocarditis, takotsubo cardiomyopathy and acute myocardial infarction. We also considered the LVGFI companion (C), derived from the quadratic mean. Additional metrics such as ejection fraction (EF), myocardial contraction fraction (MCF) and ventriculo-arterial coupling (VAC), along with their companions (MCFC and VACC) were calculated. All companion metrics (EFC, LVGFIC, MCFC, and VACC) showed sex-specific differences, not clearly reflected by the corresponding ratio-based metrics. LVGFI is mathematically coupled to both EF (with R = 0.86) and VAC (R = 0.87), which observation clarifies why these metrics not only share similar prognostic values but also identical shortcomings. We found that the newly introduced LVGFIC has incremental value compared to the single use of LVGFI, EF, or GLS, when characterizing the three patient groups.
左心室（LV）整体功能指数（LVGFI）已被引入作为一种基于容积的综合指标，用于评估心室功能。其定义公式结合了每搏输出量（SV）、收缩末期容积（ESV）、舒张末期容积（EDV）以及左心室质量/密度。作为一个无量纲比率，这个新指标存在严重局限性，需要在数学和临床层面进行评估。我们对96例患者使用心脏磁共振成像（CMRI）研究了左心室容积、各种衍生指标和整体纵向应变（GLS），以便在三个诊断组中进一步描述LVGFI：急性心肌炎、应激性心肌病和急性心肌梗死。我们还考虑了源自二次均值的LVGFI伴随指标（C）。计算了其他指标，如射血分数（EF）、心肌收缩分数（MCF）和心室动脉耦合（VAC），以及它们的伴随指标（MCFC和VACC）。所有伴随指标（EFC、LVGFIC、MCFC和VACC）均显示出性别特异性差异，而相应的基于比率的指标并未清晰反映这些差异。LVGFI在数学上与EF（R = 0.86）和VAC（R = 0.87）均相关，这一观察结果阐明了为什么这些指标不仅具有相似的预后价值，而且存在相同的缺点。我们发现，在对这三个患者组进行特征描述时，新引入的LVGFIC相较于单独使用LVGFI、EF或GLS具有增量价值。
