Lapinskas Tomas, Bučius Paulius, Urbonaitė Laura, Stabinskaitė Agnieta, Valuckienė Živilė, Jankauskaitė Lina, Benetis Rimantas, Žaliūnas Remigijus
Department of Cardiology, Medical Academy, Lithuanian University of Health Sciences, Kaunas, Lithuania.
Department of Cardiology, Medical Academy, Lithuanian University of Health Sciences, Kaunas, Lithuania.
Medicina (Kaunas). 2017;53(1):11-18. doi: 10.1016/j.medici.2017.02.001. Epub 2017 Mar 1.
Left atrium (LA) is an important biomarker of adverse cardiovascular outcomes and cerebrovascular events. This study aimed to evaluate LA myocardial deformation using cardiac magnetic resonance feature tracking (CMR-FT) in patients with acute ST-segment elevation myocardial infarction (STEMI) and secondary mitral regurgitation (MR). Additionally, to assess interobserver and intraobserver variability of the technique.
Twenty patients with STEMI underwent CMR with a 1.5Tesla MRI scanner. According to the presence of MR patients were divided into two groups: MR(+) and MR(-). Total LA strain (ɛ), passive LA strain (ɛ), and active LA strain (ɛ) were obtained. Additionally, total, passive and active strain rates (SR, SR, and SR) were calculated. To assess interobserver agreement data analysis was performed by second independent observer.
LA volumetric and functional parameters were similar in both groups. All LA strain values were significantly higher in patients with MR: ɛ (27.67±10.25 for MR(-) vs. 32.80±6.95 for MR(+); P=0.01), ɛ (15.29±7.30 for MR(-) vs. 19.22±6.04 for MR(+); P=0.01) and ɛ (12.38±4.23 for MR(-) vs. 14.44±5.19 for MR(+); P=0.03). Only SR significantly increased in patients with MR (-0.57±0.24 for MR(-) vs. -0.70±0.20 for MR(+); P=0.01). All LA deformation parameters demonstrated high interobserver and intraobserver agreement.
Conventional volumetric and functional LA parameters do not detect early changes in LA performance in patients with STEMI and secondary MR. In contrast, LA reservoir, passive and active strain are significantly higher in patients with MR. Only peak early negative strain rate substantially increases during secondary MR. LA deformation parameters derived from conventional cine images using CMR-FT technique are highly reproducible.
左心房（LA）是心血管不良结局和脑血管事件的重要生物标志物。本研究旨在利用心脏磁共振特征追踪（CMR-FT）技术评估急性ST段抬高型心肌梗死（STEMI）合并继发性二尖瓣反流（MR）患者的左心房心肌变形情况。此外，评估该技术在观察者间和观察者内的变异性。
20例STEMI患者接受了1.5特斯拉MRI扫描仪的CMR检查。根据是否存在MR将患者分为两组：MR（+）组和MR（-）组。获取左心房总应变（ɛ）、被动左心房应变（ɛ）和主动左心房应变（ɛ）。此外，计算总应变率、被动应变率和主动应变率（SR、SR和SR）。为评估观察者间的一致性，由第二位独立观察者进行数据分析。
两组患者的左心房容积和功能参数相似。MR患者的所有左心房应变值均显著更高：ɛ（MR（-）组为27.67±10.25，MR（+）组为32.80±6.95；P = 0.01），ɛ（MR（-）组为15.29±7.30，MR（+）组为19.22±6.04；P = 0.01）和ɛ（MR（-）组为12.38±4.23，MR（+）组为14.44±5.19；P = 0.03）。只有SR在MR患者中显著增加（MR（-）组为-0.57±0.24，MR（+）组为-0.70±0.20；P = 0.01）。所有左心房变形参数在观察者间和观察者内均显示出高度一致性。
传统的左心房容积和功能参数无法检测出STEMI合并继发性MR患者左心房功能的早期变化。相比之下，MR患者的左心房储存、被动和主动应变显著更高。仅在继发性MR期间，早期负向峰值应变率大幅增加。使用CMR-FT技术从传统电影图像中得出的左心房变形参数具有高度可重复性。
