Boos Christopher J, Hodkinson Pete D, Mellor Adrian, Green Nick P, Bradley Daniel, Greaves Kim, Woods David R
Department of Cardiology, Poole Hospital NHS Foundation Trust, Dorset, United Kingdom.
Echocardiography. 2013 May;30(5):534-41. doi: 10.1111/echo.12088. Epub 2013 Jan 11.
There are limited data on the effects of prolonged acute hypoxia on individual and global measures of biventricular function.
The aim of this study was to assess its effects on conventional and novel measures of biventricular function, including the recently defined E'/(A'×S') (EAS) index, obtained using pulsed-wave tissue Doppler Imaging (PWTDI) and associated blood brain natriuretic peptide (BNP) levels.
In this study, 14 healthy subjects aged 30.5 years were assessed at baseline and at >150 minutes following hypobaric hypoxia (HH) to the equivalent altitude of 4800 m for a total of 180 minutes. The combined EAS index (E'/(A' × S')) was calculated at the mitral and tricuspid annulus using data from the peak systolic (S') early (E') and late (A') diastolic filling.
It was seen that HH increased resting heart rate (63.4 ± 8.4 vs. 85.2 ± 10.2/min; P < 0.0001), cardiac output (4.6 ± 0.7 L/min vs. 6.1 ± 1.2 L/min; P < 0.0001), peak pulmonary artery systolic pressure (PASP) (26.3 ± 2.0 mmHg vs. 37.2 ± 6.3 mmHg; P < 0.0001), and reduced SpO2 (98.5 ± 1.1 vs. 72.9 ± 8.1%; P < 0.0001). There was a significant reduction in mitral (0.19 ± 0.06 vs. 0.11 ± 0.03; P < 0.0001) and tricuspid (0.12 ± 0.04 vs. 0.09 ± 0.03; P = 0.03) EAS indices, but no change in left or right ventricular myocardial performance (Tei) indices, global left ventricular (LV) longitudinal systolic strain, BNP levels, or estimated filling pressures (E/E'). Only reducing SpO2 remained as an independent predictor of PASP on multivariate analysis (overall R(2) = 0.77; P < 0.0001). The right and LV EAS indices were significantly correlated (r = 0.45; 95% CI: 0.07-0.7; P = 0.02).
The conclusion from this study was that acute prolonged HH does not adversely affect resting global biventricular function and there is evidence of linked right and LV responses.
关于长期急性缺氧对双心室功能的个体及整体指标影响的数据有限。
本研究旨在评估其对双心室功能的传统及新指标的影响，包括使用脉冲波组织多普勒成像（PWTDI）获得的最近定义的E'/(A'×S')（EAS）指数以及相关的血脑钠肽（BNP）水平。
在本研究中，对14名年龄30.5岁的健康受试者在基线时以及在低压缺氧（HH）至海拔4800米等效高度共180分钟后>150分钟时进行评估。使用来自收缩期峰值（S'）、舒张早期（E'）和晚期（A'）充盈的数据计算二尖瓣和三尖瓣环处的联合EAS指数（E'/(A'×S')）。
可见HH使静息心率增加（63.4±8.4对85.2±10.2次/分钟；P<0.0001）、心输出量增加（4.6±0.7升/分钟对6.1±1.2升/分钟；P<0.0001）、肺动脉收缩压峰值（PASP）增加（26.3±2.0毫米汞柱对37.2±6.3毫米汞柱；P<0.0001），并使SpO2降低（98.5±1.1对72.9±8.1%；P<0.0001）。二尖瓣（0.19±0.06对0.11±0.03；P<0.0001）和三尖瓣（0.12±0.04对0.09±0.03；P = 0.03）EAS指数显著降低，但左或右心室心肌性能（Tei）指数、整体左心室（LV）纵向收缩应变、BNP水平或估计充盈压（E/E'）无变化。在多变量分析中，仅SpO2降低仍然是PASP的独立预测因子（总体R(2)=0.77；P<0.0001）。右心室和左心室EAS指数显著相关（r = 0.45；95%CI：0.07 - 0.7；P = 0.02）。
本研究的结论是急性长期HH不会对静息状态下的整体双心室功能产生不利影响，且有证据表明右心室和左心室反应相关。
