Gama Filho University, Rio de Janeiro, Rio de Janeiro, Brazil.
Clinics (Sao Paulo). 2011;66(2):203-9. doi: 10.1590/s1807-59322011000200004.
Exercise oxygen pulse (O₂ pulse), a surrogate for stroke volume and arteriovenous oxygen difference, has emerged as an important variable obtained during cardiopulmonary exercise testing.
We hypothesized that the O₂ pulse curve pattern response to a maximal cycling ramp protocol exhibits a stable linear pattern in subjects reevaluated under the same clinical conditions.
We retrospectively studied 100 adults (80 males), mean age at baseline of 59 + 12 years, who performed two cardiopulmonary exercise testings (median interval was 15 months), for clinical and/or exercise prescription reasons. The relative O₂ pulse was calculated by dividing its absolute value by body weight. Subjects were classified into quintiles of relative O₂ pulse. Cardiopulmonary exercise testing results and the O₂ pulse curve pattern, expressed by its slope and intercept, were compared among quintiles of relative O₂ pulse at both cardiopulmonary exercise testings.
After excluding the first minute of CPX (rest-exercise transition), the relative O₂ pulse curve exhibited a linear increase, as demonstrated by high coefficients of determination (R² from 0.75 to 0.90; p < 0.05 for all quintiles). Even though maximum oxygen uptake and relative O₂ pulse were significantly higher in the second cardiopulmonary exercise testing for each quintile of relative O₂ pulse (p < 0.05 for all comparisons), no differences were found when slopes and intercepts were compared between the first and second cardiopulmonary exercise testings (p > 0.05 for all comparisons; except for intercept in the 5th quintile).
Excluding the rest-exercise transition, the relative O₂ pulse exhibited a stable linear increase throughout maximal exercise in adults that were retested under same clinical conditions.
运动氧脉搏（O₂ 脉搏）是每搏输出量和动静脉氧差的替代指标，已成为心肺运动测试中获得的一个重要变量。
我们假设在相同的临床条件下重新评估时，最大踏车递增方案的 O₂ 脉搏曲线模式反应表现出稳定的线性模式。
我们回顾性研究了 100 名成年人（80 名男性），他们在基线时的平均年龄为 59 + 12 岁，因临床和/或运动处方原因进行了两次心肺运动测试（中位数间隔为 15 个月）。相对 O₂ 脉搏通过将其绝对值除以体重来计算。将受试者分为相对 O₂ 脉搏的五分位数。在两次心肺运动测试中，比较了相对 O₂ 脉搏五分位数的心肺运动测试结果和 O₂ 脉搏曲线模式（斜率和截距表示）。
排除 CPX 的前 1 分钟（休息-运动过渡）后，相对 O₂ 脉搏曲线呈线性增加，决定系数高（所有五分位数的 R² 从 0.75 到 0.90；所有比较的 p < 0.05）。尽管每个相对 O₂ 脉搏五分位数的第二次心肺运动测试的最大摄氧量和相对 O₂ 脉搏均显著升高（所有比较的 p < 0.05），但在第一次和第二次心肺运动测试之间比较斜率和截距时未发现差异（所有比较的 p > 0.05；除了第 5 个五分位数的截距）。
在排除休息-运动过渡后，在相同临床条件下重新评估的成年人中，相对 O₂ 脉搏在整个最大运动中呈稳定的线性增加。
