Sonaglioni Andrea, Esposito Valentina, Caruso Chiara, Nicolosi Gian Luigi, Bianchi Stefano, Lombardo Michele, Gensini Gian Franco, Ambrosio Giuseppe
Department of Cardiology.
Department of Gynecology and Obstetrics, Ospedale San Giuseppe MultiMedica IRCCS, Milan.
J Cardiovasc Med (Hagerstown). 2021 Oct 1;22(10):767-779. doi: 10.2459/JCM.0000000000001213.
Left ventricular (LV) contractility during noncomplicated pregnancy has been previously investigated by two-dimensional speckle-tracking echocardiography (2D-STE), with conflicting results. Chest abnormalities might affect myocardial strain parameters, yet this issue has not been previously investigated during pregnancy. We evaluated the influence of chest conformation on myocardial strain parameters in healthy pregnant women.
Between October 2019 and February 2020, 50 healthy pregnant women (32.3 ± 4.0 years old) were consecutively studied. They underwent obstetric visit, assessment of chest shape by modified Haller index (MHI; chest transverse diameter over the distance between sternum and spine) and transthoracic echocardiography implemented with 2D-STE analysis of all myocardial strain parameters in the first trimester (12-14 weeks), third trimester (36-38 weeks) and 6-9 weeks after delivery.
LV ejection fraction remained substantially unchanged (P = 0.13), while on the average all myocardial strain parameters showed a small but significant decrease during pregnancy, and recovered postpartum (all P < 0.001). Women with concave-shaped chest wall (MHI > 2.5, n = 29), and those with normal chest conformation (MHI ≤ 2.5, n = 21) were then separately analyzed. Pregnant women with MHI above 2.5, but not those with MHI 2.5 or less, showed a progressive but reversible decrease in all myocardial strain parameters (all P < 0.001). MHI was strongly correlated with LV global longitudinal strain (r = -0.87) and LV global circumferential strain (r = -0.83) in the third trimester of pregnancy.
Myocardial strain impairment during healthy pregnancy may not reflect intrinsic myocardial dysfunction but rather intraventricular dyssynchrony related to a narrow antero-posterior chest diameter and rise in the diaphragm, with consequent extrinsic myocardial compression.
以往曾采用二维斑点追踪超声心动图（2D-STE）研究非并发症妊娠期间的左心室（LV）收缩性，但结果相互矛盾。胸部异常可能会影响心肌应变参数，然而此前尚未在妊娠期间对此问题进行研究。我们评估了胸部形态对健康孕妇心肌应变参数的影响。
在2019年10月至2020年2月期间，连续研究了50名健康孕妇（年龄32.3±4.0岁）。她们接受了产科检查，通过改良哈勒指数（MHI；胸部横径与胸骨和脊柱之间距离的比值）评估胸部形状，并在孕早期（12 - 14周）、孕晚期（36 - 38周）及产后6 - 9周进行经胸超声心动图检查，同时采用2D-STE分析所有心肌应变参数。
左心室射血分数基本保持不变（P = 0.13），而平均而言，所有心肌应变参数在妊娠期间均呈现轻微但显著的下降，并在产后恢复（所有P < 0.001）。然后分别分析胸壁呈凹形（MHI > 2.5，n = 29）和胸部形态正常（MHI≤2.5，n = 21）的女性。MHI高于2.5的孕妇，而非MHI为2.5或更低的孕妇，所有心肌应变参数均呈现逐渐但可逆的下降（所有P < 0.001）。在妊娠晚期，MHI与左心室整体纵向应变（r = -0.87）和左心室整体圆周应变（r = -0.83）密切相关。
健康妊娠期间的心肌应变受损可能并非反映内在心肌功能障碍，而是与前后胸径变窄和膈肌上升相关的心室内不同步，进而导致外在心肌受压。
