亲爱的研友该休息了!由于当前在线用户较少,发布求助请尽量完整地填写文献信息,科研通机器人24小时在线,伴您度过漫漫科研夜!身体可是革命的本钱,早点休息,好梦!

Blood coagulation changes at high altitude predisposing to pulmonary hypertension.

医学 肺动脉高压 凝结 高度(三角形) 心脏病学 高海拔对人类的影响 内科学 重症监护医学 几何学 数学 解剖
作者
Inderjeet Singh,I. S. Chohan
出处
期刊:Heart [BMJ]
卷期号:34 (6): 611-617 被引量:63
标识
DOI:10.1136/hrt.34.6.611
摘要

Blood coagulation studies were carried out in 38 Indian soldiers who were resident at altitudes between I2,000 and i8,0oo feet for 2 years.Compared with I6 sea-level controls, 6 of these 38 subjects who had developed pulmonary hypertension during their stay at high altitude showed a significant increase ofplasmafibrinogen,fibrinolytic activity, platelet adhesiveness, plateletfactor 3, factor V, and factor VIII.In the remaining 32 subjects who did not develop pulmonary hypertension there was a significant increase of plasma fibrinogen and fibrinolytic activity only.The above differences between subjects who develop pulmonary hypertension at high altitude and those who do not develop pulmonary hypertension suggest that high altitude pulmonary hyper- tension is of occlusive origin and is dependent on changes in blood coagulation at high altitude.The pathogenesis of high altitude pulmonary hypertension is far from clear.Rotta et al. (I956) found a striking inverse correlation be- tween the degree of arterial oxygen saturation and the level of the mean pulmonary arterial pressure.However, with acetylcholine and oxygen therapy, pulmonary hypertension de- creased only to the extent of I5 to 20 per cent.Evidently, hypoxia does not affect the pulmonary arterial pressure directly to any conspicuous extent.Campos and Iglesias (I957) observed an obvious dilatation of the vascular bed of the lungs.There is also thickening of the muscu- lar layer of the small pulmonary arteries and muscularization of the pulmonary arterioles (Arias-Stella and Saldania, I962).Pen'ialoza et al. (I963) attributed high altitude pulmonary hypertension to increased pulmonary vascular resistance resulting from widespread narrowing of the lumen of the pulmonary blood vessels on account of these changes.However, in our experience with soldiers temporarily posted at high altitudes, who develop pulmonary hypertension and die of it, these changes are not prominent (see below).It seems more likely that these changes are not causal but secondary to long-standing hypertension.The pulmonary blood flow, as indicated by a nor- mal cardiac output, is not increased in pul- monary hypertension.In itself, therefore, an increased pulmonary vascular bed is not con- tributory.In the absence of these changes, dilatation of the vascular bed may be found Received 29 July 197I.in association with an increased pulmonary blood volume, but without pulmonary hyper- tension.Polycythaemia per se does not seem to pre- dispose to pulmonary hypertension.Pulmon- ary hypertension may be present without polycythaemia, or it may persist after the red blood cell count has returned to normal when the individual has returned to sea-level.In our soldiers who are temporarily posted from sea-level to altitudes in the Himalayas, the symptoms of pulmonary hypertension begin after a stay of 5 to 42 months at high altitude.After the initial onset of the disease, periodic returns to sea-level on leave for 2 to 3 months once a year do not alter the picture.The hypertension either persists at sea-level or, if it abates, it reappears within 2 to 3 weeks after the individual returns to high altitude.Though pulmonary vasoconstriction, in- creased pulmonary blood volume, and poly- cythaemia may have some role in the patho- genesis of high altitude pulmonary hyperten- sion, these bases do not explain its slow dis- appearance or persistence when the subjects return to sea-level.In a previous study (Singh et al., i965), based on necropsy findings in high altitude pulmonary hypertension, we reported the presence of numerous occluding fibrin throm- bi in the smaller branches of the pulmonary artery.Several segments of the pulmonary artery and its larger branches showed small but patchy atherosclerotic changes and evi- dence of repeated episodes of thrombosis.A on August 16,
最长约 10秒,即可获得该文献文件

科研通智能强力驱动
Strongly Powered by AbleSci AI
更新
PDF的下载单位、IP信息已删除 (2025-6-4)

科研通是完全免费的文献互助平台,具备全网最快的应助速度,最高的求助完成率。 对每一个文献求助,科研通都将尽心尽力,给求助人一个满意的交代。
实时播报
10秒前
正直的松鼠完成签到 ,获得积分10
29秒前
核桃发布了新的文献求助10
1分钟前
Xw关闭了Xw文献求助
1分钟前
1分钟前
Xw关闭了Xw文献求助
1分钟前
2分钟前
Swear完成签到 ,获得积分10
2分钟前
勤恳冰淇淋完成签到 ,获得积分10
2分钟前
2分钟前
El发布了新的文献求助10
2分钟前
2分钟前
李健应助El采纳,获得10
2分钟前
义气雁完成签到 ,获得积分10
3分钟前
3分钟前
xiongdi521发布了新的文献求助10
3分钟前
美罗培南完成签到 ,获得积分10
3分钟前
lige完成签到 ,获得积分10
3分钟前
3分钟前
3分钟前
二十四桥完成签到 ,获得积分10
3分钟前
直觉应助背后的鞋垫采纳,获得10
3分钟前
桦奕兮完成签到 ,获得积分10
3分钟前
Akim应助Borhan采纳,获得10
4分钟前
4分钟前
jjjjj发布了新的文献求助10
4分钟前
Liiiiiiiiii发布了新的文献求助10
4分钟前
Eva完成签到 ,获得积分10
4分钟前
上官若男应助Liiiiiiiiii采纳,获得10
4分钟前
Liufgui应助jjjjj采纳,获得10
4分钟前
4分钟前
酷波er应助科研通管家采纳,获得10
4分钟前
科研通AI2S应助科研通管家采纳,获得10
4分钟前
核桃发布了新的文献求助30
5分钟前
田様应助最最最采纳,获得10
5分钟前
5分钟前
5分钟前
不懂白完成签到 ,获得积分10
6分钟前
6分钟前
Borhan发布了新的文献求助10
6分钟前
高分求助中
The Mother of All Tableaux: Order, Equivalence, and Geometry in the Large-scale Structure of Optimality Theory 3000
A new approach to the extrapolation of accelerated life test data 1000
ACSM’s Guidelines for Exercise Testing and Prescription, 12th edition 500
Indomethacinのヒトにおける経皮吸収 400
Phylogenetic study of the order Polydesmida (Myriapoda: Diplopoda) 370
基于可调谐半导体激光吸收光谱技术泄漏气体检测系统的研究 350
Robot-supported joining of reinforcement textiles with one-sided sewing heads 320
热门求助领域 (近24小时)
化学 材料科学 医学 生物 工程类 有机化学 生物化学 物理 内科学 纳米技术 计算机科学 化学工程 复合材料 遗传学 基因 物理化学 催化作用 冶金 细胞生物学 免疫学
热门帖子
关注 科研通微信公众号,转发送积分 3990075
求助须知:如何正确求助?哪些是违规求助? 3532108
关于积分的说明 11256369
捐赠科研通 3271016
什么是DOI,文献DOI怎么找? 1805171
邀请新用户注册赠送积分活动 882270
科研通“疑难数据库(出版商)”最低求助积分说明 809228