University Hospital of Bern, Cardiology, Bern, Switzerland.
Chest. 2010 Feb;137(2):388-92. doi: 10.1378/chest.09-1355. Epub 2009 Sep 25.
Chronic mountain sickness (CMS) is an important public health problem and is characterized by exaggerated hypoxemia, erythrocytosis, and pulmonary hypertension. While pulmonary hypertension is a leading cause of morbidity and mortality in patients with CMS, it is relatively mild and its underlying mechanisms are not known. We speculated that during mild exercise associated with daily activities, pulmonary hypertension in CMS is much more pronounced.
We estimated pulmonary artery pressure by using echocardiography at rest and during mild bicycle exercise at 50 W in 30 male patients with CMS and 32 age-matched, healthy control subjects who were born and living at an altitude of 3,600 m.
The modest, albeit significant difference of the systolic right-ventricular-to-right-atrial pressure gradient between patients with CMS and controls at rest (30.3 +/- 8.0 vs 25.4 +/- 4.5 mm Hg, P 5 .002) became more than three times larger during mild bicycle exercise (56.4 +/- 19.0 vs 39.8 +/- 8.0 mm Hg, P < .001).
Measurements of pulmonary artery pressure at rest greatly underestimate pulmonary artery pressure during daily activity in patients with CMS. The marked pulmonary hypertension during mild exercise associated with daily activity may explain why this problem is a leading cause of morbidity and mortality in patients with CMS.
慢性山病（CMS）是一个重要的公共卫生问题，其特征是明显的低氧血症、红细胞增多症和肺动脉高压。虽然肺动脉高压是 CMS 患者发病率和死亡率的主要原因，但它相对较轻，其潜在机制尚不清楚。我们推测，在与日常活动相关的轻度运动期间，CMS 中的肺动脉高压更为明显。
我们使用超声心动图在休息时和 CMS 男性患者 30 名和年龄匹配的、居住在海拔 3600 米的健康对照组 32 名在 50 W 轻度自行车运动时评估肺动脉压。
CMS 患者和对照组在休息时的收缩期右心室 - 右心房压力梯度有适度但显著的差异（30.3 +/- 8.0 对 25.4 +/- 4.5 mmHg，P <.002），在轻度自行车运动时增加了三倍以上（56.4 +/- 19.0 对 39.8 +/- 8.0 mmHg，P <.001）。
在 CMS 患者的日常活动中，休息时测量肺动脉压大大低估了肺动脉压。与日常活动相关的轻度运动时明显的肺动脉高压可能解释了为什么这个问题是 CMS 患者发病率和死亡率的主要原因。
