Hanaoka Masayuki, Kogashi Kaoru, Droma Yunden, Urushihata Kazuhisa, Kubo Keishi
The First Department of Medicine, Shinshu University School of Medicine, Japan.
Intern Med. 2011;50(24):2967-73. doi: 10.2169/internalmedicine.50.5942. Epub 2011 Dec 15.
A recent study concerning high-altitude pulmonary edema (HAPE), a non-cardiogenic pulmonary edema, suggested that it is initially a hydrostatic-type pulmonary edema. We suspect that some extent of cardiac insufficiency may likely relate to the mechanism of the development of this disease.
By Doppler echocardiography, the Tei index (a new quantitative index proposed for the evaluation of global myocardial performance) and the systolic pulmonary artery pressure (sPAP) were measured before and after 30 minutes of hypoxic breathing.
Eleven HAPE-susceptible subjects (HAPE-s) and nine HAPE-resistant subjects (HAPE-r).
The results of Tei index indicated an enhanced left myocardial performance but an impaired right performance in HAPE-s during hypoxic breathing. The sPAP of HAPE-s was significantly increased after hypoxic breathing, which was not correlated with the heart functions such as right ventricular (RV) Tei index, cardiac index (CI), percent ejection fraction (EF%) and percent fractional shortening (FS%) under hypoxic condition. Comparatively, the HAPE-r subjects did not show such significant changes of Tei index after hypoxic breathing. The results suggested that a paradoxical myocardial performance, in a format of an augmented left ventricular (LV) in contrast to an attenuated RV, was observed in the HAPE-s exposed to acute hypoxia.
The responses of the left and right myocardial performances to hypoxia may be involved in the pathogenesis of HAPE.
最近一项关于高原肺水肿（HAPE，一种非心源性肺水肿）的研究表明，其最初是一种静水压型肺水肿。我们怀疑一定程度的心脏功能不全可能与该疾病的发生机制有关。
通过多普勒超声心动图，在低氧呼吸30分钟前后测量Tei指数（一种为评估整体心肌功能而提出的新的定量指标）和收缩期肺动脉压（sPAP）。
11名高原肺水肿易感受试者（HAPE-s）和9名高原肺水肿抵抗受试者（HAPE-r）。
Tei指数结果表明，在低氧呼吸期间，HAPE-s受试者左心室心肌功能增强，但右心室功能受损。HAPE-s受试者在低氧呼吸后sPAP显著升高，这与低氧条件下的心脏功能如右心室（RV）Tei指数、心脏指数（CI）、射血分数百分比（EF%）和缩短分数百分比（FS%）无关。相比之下，HAPE-r受试者在低氧呼吸后Tei指数没有出现如此显著的变化。结果表明，在暴露于急性低氧的HAPE-s受试者中，观察到一种矛盾的心肌功能表现，即左心室（LV）增强而右心室减弱。
左右心室心肌功能对低氧的反应可能参与了高原肺水肿的发病机制。
