Individuals born prematurely have smaller hearts, cardiac limitations to exercise, and increased overall cardiometabolic risk. The cardiac effects of acute hypoxia exposure as another physiologic stressor remain under explored. The purpose of this study was to determine the effects of hypoxia on ventricular function in adults born preterm. Adults born moderately to extremely preterm (≤32 weeks gestation or <1500 g, N = 32) and born at term (N = 18) underwent cardiac magnetic resonance imaging under normoxic (21% O₂) and hypoxic (12% O₂) conditions to assess cardiovascular function. In normoxia, cardiac function parameters were similar between groups. During hypoxia, the right ventricular (RV) contractile response was significantly greater in participants born premature, demonstrated by greater increases in RV ejection fraction (EF) (p = 0.002), ventricular-vascular coupling (VVC) (p = 0.004), and strain (p < 0.0001) measures compared to term-born participants, respectively. Left ventricular contractile reserve was similar to term-born participants. Adults born preterm exhibit an exaggerated contractile response to acute hypoxia, particularly in the RV. This suggests that adults born preterm may have contractile reserve, despite the lack of volume reserve identified in previous exercise studies. However, this exaggerated and hyper-adapted response may also increase their risk for late RV failure.

中文翻译：

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早产成人对缺氧的过度心脏收缩反应

过早出生的人心脏较小，心脏运动受限，整体心脏代谢风险增加。作为另一种生理压力源的急性缺氧暴露对心脏的影响仍在探索中。本研究的目的是确定缺氧对早产成人心室功能的影响。中度至极早产儿（≤ 32周妊娠或 <1500 g，N = 32）和足月出生（N = 18）的成人在常氧（21% O ₂）和缺氧（12% O ₂）下接受心脏磁共振成像) 评估心血管功能的条件。在常氧条件下，各组之间的心脏功能参数相似。在缺氧期间，早产参与者的右心室 (RV) 收缩反应显着更大，这表现为 RV 射血分数 (EF) ( p = 0.002)、心室-血管耦合 (VVC) ( p = 0.004) 和应变 ( p< 0.0001) 分别与足月出生的参与者进行比较。左心室收缩储备与足月出生的参与者相似。早产的成年人对急性缺氧表现出夸张的收缩反应，尤其是在 RV 中。这表明早产的成年人可能有收缩储备，尽管在之前的运动研究中缺乏容量储备。然而，这种夸大和过度适应的反应也可能增加他们晚期 RV 失败的风险。