Horii M, Takasaki I, Ohtsuka K, Tsukiyama H, Takahashi A, Hatori Y, Hakuta T
Clin Cardiol. 1987 Apr;10(4):238-42. doi: 10.1002/clc.4960100406.
The purpose of this study is to record continuously electrocardiograms of alpinists during different activities practiced in mountaineering, compare heart rate and QT interval at high altitude with those at sea level, and compare alpinists with nonalpinists. Analysis was attempted on 14 alpinists (9 male, 5 female, ages 26-45) to determine changes in heart rate and QT interval using continuous ambulatory electrocardiograms recorded at sea level and high altitude. Between 1983 and 1984, 9 of 14 alpinists (6 male, 3 female) were subjected to the study at high altitude, that is, at Mt. Kangchenjunga (Himalaya), Mt. Satopanth (Himalaya), and Mt. Jitudake (Butan), 4400 to 7800 m (mean 5710 m). The following were noted: Heart rate at high altitude was significantly higher both in daytime and nighttime. The circadian rhythm of the heart rate disappeared at extremely high altitude in several alpinists. A high correlation was noted between measured QT interval (QTm) and RR interval (r = 0.81, p = 0.005). Nighttime QTm at high altitude was prolonged in comparison with that of daytime so far as the RR interval remained the same. At high altitude, the nighttime corrected QT interval (QTc) was also significantly prolonged in spite of shortened RR interval. The mechanism of QTc prolongation is not clear. Many factors may impact on the QT interval during mountaineering.
本研究的目的是持续记录登山运动员在登山过程中进行不同活动时的心电图，比较高海拔地区与海平面的心率和QT间期，并将登山运动员与非登山运动员进行比较。对14名登山运动员（9名男性，5名女性，年龄26 - 45岁）进行分析，通过记录他们在海平面和高海拔地区的动态心电图来确定心率和QT间期的变化。1983年至1984年间，14名登山运动员中的9名（6名男性，3名女性）在高海拔地区进行了研究，即干城章嘉峰（喜马拉雅山脉）、萨托潘特峰（喜马拉雅山脉）和吉图达凯峰（不丹），海拔4400至7800米（平均5710米）。结果如下：高海拔地区白天和夜间的心率均显著较高。在极高海拔地区，部分登山运动员的心率昼夜节律消失。测量的QT间期（QTm）与RR间期之间存在高度相关性（r = 0.81，p = 0.005）。在RR间期相同的情况下，高海拔地区夜间的QTm比白天延长。在高海拔地区，尽管RR间期缩短，但夜间校正QT间期（QTc）也显著延长。QTc延长的机制尚不清楚。登山过程中许多因素可能会影响QT间期。
