Gunturiz-Beltrán Clara, Borràs Roger, Alarcón Francisco, Garre Paz, Figueras I Ventura Rosa M, Benito Eva M, Caixal Gala, Althoff Till F, Tolosana José María, Arbelo Elena, Roca-Luque Ivo, Prat-González Susanna, Perea Rosario Jesús, Brugada Josep, Sitges Marta, Guasch Eduard, Mont Lluís
Institut Clínic Cardiovascular, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain; Institut d́Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain; Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), Spain.
Institut Clínic Cardiovascular, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain; Institut d́Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain; Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Spain.
Rev Esp Cardiol (Engl Ed). 2023 Mar;76(3):173-182. doi: 10.1016/j.rec.2022.06.010. Epub 2022 Jul 7.
Late gadolinium-enhanced cardiac magnetic resonance (LGE-CMR) allows noninvasive detection of left atrial fibrosis in patients with atrial fibrillation (AF). However, whether the same methodology can be used in the right atrium (RA) remains unknown. Our aim was to define a standardized threshold to characterize RA fibrosis in LGE-CMR.
A 3 Tesla LGE-CMR was performed in 53 individuals; the RA was segmented, and the image intensity ratio (IIR) calculated for the RA wall using 1 557 767 IIR pixels (40 994±10 693 per patient). The upper limit of normality of the IIR (mean IIR+2 standard deviations) was estimated in healthy volunteers (n=9), and patients who had undergone previous typical atrial flutter ablation (n=9) were used to establish the dense scar threshold. Paroxysmal and persistent AF patients (n=10 each) were used for validation. IIR values were correlated with a high-density bipolar voltage map in 15 patients undergoing AF ablation.
The upper normality limit (total fibrosis threshold) in healthy volunteers was set at an IIR = 1.21. In the postablation group, 60% of the maximum IIR pixel (dense fibrosis threshold) was calculated as IIR = 1.29. Endocardial bipolar voltage showed a weak but significant correlation with IIR. The overall accuracy between the electroanatomical map and LGE-CMR to characterize fibrosis was 56%.
An IIR > 1.21 was determined to be the threshold for the detection of right atrial fibrosis, while an IIR > 1.29 differentiates interstitial fibrosis from dense scar. Despite differences between the left and right atria, fibrosis could be assessed with LGE-CMR using similar thresholds in both chambers.
延迟钆增强心脏磁共振成像（LGE-CMR）能够无创检测心房颤动（AF）患者的左心房纤维化。然而，同样的方法能否用于右心房（RA）尚不清楚。我们的目的是确定一个标准化阈值，以在LGE-CMR中表征RA纤维化。
对53名个体进行3特斯拉LGE-CMR检查；对RA进行分割，并使用1 557 767个图像强度比（IIR）像素（每位患者40 994±10 693个）计算RA壁的IIR。在健康志愿者（n = 9）中估计IIR的正常上限（平均IIR + 2个标准差），并使用先前接受过典型心房扑动消融的患者（n = 9）来确定致密瘢痕阈值。阵发性和持续性AF患者（各n = 10）用于验证。在15名接受AF消融的患者中，将IIR值与高密度双极电压图进行相关性分析。
健康志愿者的正常上限（总纤维化阈值）设定为IIR = 1.21。在消融后组中，最大IIR像素的60%（致密纤维化阈值）计算为IIR = 1.29。心内膜双极电压与IIR呈弱但显著的相关性。用于表征纤维化的电解剖图与LGE-CMR之间的总体准确率为56%。
确定IIR > 1.21为检测右心房纤维化的阈值，而IIR > 1.29可区分间质纤维化与致密瘢痕。尽管左心房和右心房存在差异，但在两个心房中使用相似的阈值，LGE-CMR均可评估纤维化。
