Institute of Cardiovascular Diseases of PLA, the Second Affiliated Hospital, Third Military Medical University (Army Medical University), Chongqing, China.
Department of Cardiology, the Second Affiliated Hospital, Third Military Medical University (Army Medical University), Chongqing, China.
J Clin Hypertens (Greenwich). 2021 Jun;23(6):1133-1143. doi: 10.1111/jch.14235. Epub 2021 Mar 6.
Acute high-altitude (HA) exposure induces physiological responses of the heart and blood pressure (BP). However, few studies have investigated the responses associated with dipper and non-dipper BP patterns. In this prospective study, 72 patients underwent echocardiography and 24-h ambulatory BP testing at sea level and HA. Patients were divided into dipper and non-dipper groups according to BP at sea level. Acute HA exposure elevated 24-h systolic and diastolic BP and increased BP variability, particularly in the morning. Moreover, acute exposure increased left ventricular torsion, end-systolic elastance, effective arterial elastance, and untwisting rate, but reduced peak early diastolic velocity/late diastolic velocity and peak early diastolic velocity/early diastolic velocity, implying enhanced left ventricular systolic function but impaired filling. Dippers showed pronounced increases in night-time BP, while non-dippers showed significant elevation in day-time BP, which blunted differences in nocturnal BP fall, and lowest night-time and evening BP. Dippers had higher global longitudinal strain, torsion, and untwisting rates after acute HA exposure. Variations in night-time systolic BP correlated with variations in torsion and global longitudinal strain. Our study firstly demonstrates BP and cardiac function variations during acute HA exposure in different BP patterns and BP increases in dippers at night, while non-dippers showed day-time increases. Furthermore, enhanced left ventricular torsion and global longitudinal strain are associated with BP changes. Non-dippers showed poor cardiac compensatory and maladaptive to acute HA exposure. However, the exact mechanisms involved need further illumination.
急性高海拔（HA）暴露会引起心脏和血压（BP）的生理反应。然而，很少有研究调查与杓型和非杓型 BP 模式相关的反应。在这项前瞻性研究中，72 名患者在海平面和 HA 进行了超声心动图和 24 小时动态血压检测。根据海平面 BP 将患者分为杓型和非杓型组。急性 HA 暴露会升高 24 小时收缩压和舒张压，并增加 BP 变异性，尤其是在早上。此外，急性暴露会增加左心室扭转、收缩末期弹性、有效动脉弹性和扭转率，但会降低峰值早期舒张速度/晚期舒张速度和峰值早期舒张速度/早期舒张速度，表明左心室收缩功能增强，但充盈受损。杓型患者夜间 BP 明显升高，而非杓型患者日间 BP 显著升高，夜间 BP 下降幅度和最低夜间和傍晚 BP 差异减小。急性 HA 暴露后，杓型患者的整体纵向应变、扭转和扭转率均升高。夜间收缩压的变化与扭转和整体纵向应变的变化相关。我们的研究首次在不同 BP 模式下，在急性 HA 暴露期间，以及在夜间的杓型患者中，观察到 BP 和心脏功能的变化，而非杓型患者在白天则出现 BP 升高。此外，增强的左心室扭转和整体纵向应变与 BP 变化相关。非杓型患者的心脏代偿和适应急性 HA 暴露能力较差。然而，需要进一步研究来阐明具体的机制。
