Heart Division, Royal Brompton & Harefield NHS Foundation Trust, London, UK.
1st Department of Cardiology, Poznan University of Medical Sciences, Poznan, Poland.
J Cardiovasc Electrophysiol. 2020 Jun;31(6):1452-1461. doi: 10.1111/jce.14461. Epub 2020 Apr 24.
We assessed findings in cardiac magnetic resonance (CMR) as predictors of ventricular tachycardia (VT) after myocardial infarction (MI), which could allow for more precise identification of patients at risk of sudden cardiac death.
Forty-eight patients after prior MI were enrolled and divided into two groups: with (n = 24) and without (n = 24) VT. VT was confirmed by electrophysiological study and exit site was estimated based on 12-lead electrocardiogram. All patients underwent CMR with late gadolinium enhancement.
The examined groups did not differ significantly in clinical and demographical parameters (including LV ejection fraction). There was a significant difference in the infarct age between the VT and non-VT group (15.8 ± 8.4 vs 7.1 ± 6.7 years, respectively; P = .002), with the cut-off point at the level of 12 years. In the scar core, islets of heterogeneous myocardium were revealed. They were defined as areas of potentially viable myocardium within or adjacent to the core scar. The number of islets was the strongest independent predictor of VT (odds ratio [OR], 1.42; confidence interval [CI], 1.17-1.73), but total islet size and the largest islet area were also significantly higher in the VT group (OR, 1.04; CI, 1.02-1.07 and OR, 1.16; CI, 1.01-1.27, respectively). Myocardial segments with fibrosis forming 25%-75% of the ventricular wall were associated with a higher incidence of VT (7.5 ± 2.1 vs 5.7 ± 2.6; P = .014). Three-dimension CMR reconstruction confirmed good correlation of the location of the islets/channels with VT exit site during electroanatomical mapping in five cases.
The identification and quantification of islets of heterogeneous myocardium within the scar might be useful for predicting VT in patients after MI.
我们评估了心脏磁共振（CMR）检查中的发现，这些发现可预测心肌梗死后的室性心动过速（VT），从而更精确地识别发生心源性猝死风险的患者。
共纳入 48 例心肌梗死后患者，将其分为伴有（n=24）和不伴有（n=24）VT 两组。VT 通过电生理研究证实，VT 出口基于 12 导联心电图进行估计。所有患者均接受钆延迟增强心脏磁共振检查。
两组患者的临床和人口统计学参数（包括左心室射血分数）无显著差异。VT 组和非 VT 组的梗死年龄有显著差异（分别为 15.8±8.4 岁和 7.1±6.7 岁；P=0.002），12 岁为截断点。在瘢痕核心中，显示出不均匀心肌岛。这些是指核心瘢痕内或其附近潜在存活心肌的区域。心肌岛的数量是 VT 的最强独立预测因子（比值比[OR]，1.42；95%置信区间[CI]，1.17-1.73），但 VT 组的总心肌岛大小和最大心肌岛面积也显著更高（OR，1.04；95%CI，1.02-1.07 和 OR，1.16；95%CI，1.01-1.27）。纤维化形成心室壁 25%-75%的心肌节段与 VT 发生率较高相关（7.5±2.1 比 5.7±2.6；P=0.014）。三维 CMR 重建在 5 例患者中证实，心肌岛/通道的位置与电解剖标测中的 VT 出口之间具有良好的相关性。
在心肌梗死后患者中，瘢痕内不均匀心肌岛的识别和定量可能有助于预测 VT。
