Brubaker P H, Berry M J, Brozena S C, Morley D L, Walter J D, Paolone A M, Bove A A
Heart Failure and Transplant Center, Temple University Hospital, Philadelphia, PA 19140.
Med Sci Sports Exerc. 1993 Feb;25(2):191-6.
The ventilatory threshold (VT) has been suggested as a method for determining exercise training intensity in cardiac transplant patients (CTPs). Since the VT has not been validated against the more accepted marker of the anaerobic threshold, the lactate threshold (LT), in CTPs, the purpose of this investigation was to compare the VT to the LT within, as well as between, CTPs and normal subjects (NLs). Ten male orthotopic CTPs and 10 age, size, and gender matched NLs were exercised to symptom-limited maximal levels following incremental treadmill protocols. The VT was determined using the V-slope method, and the LT was identified using the log-log transformation method. The NLs and significantly higher absolute levels of VO2 at both the VT (1298.6 +/- 78.5 vs 919.0 +/- 57.2 ml.min-1) and LT (1561.1 +/- 144.2 vs 921.6 +/- 47.6 ml.min-1) compared with the CTPs. However, there was no significant difference in the relative VO2 (% peak) between CTPs and NLs at the VT (57.2 +/- 3.0 vs 49.0 +/- 3.5%) or LT (58.2 +/- 3.3 vs 58.5 +/- 4.9%), respectively. Within groups there was no significant difference between the VT and LT for either CTPs (919.0 +/- 57.2 vs 921.6 +/- 47.6 ml.min-1 or NLs (1298.6 +/- 78.5 vs 1561.1 +/- 144.2 ml.min-1). From the results of this investigation it appears that the VT may be used as an indicator of LT in CTPs and is within a range acceptable for clinical application.(ABSTRACT TRUNCATED AT 250 WORDS)
通气阈值（VT）被认为是一种确定心脏移植患者（CTP）运动训练强度的方法。由于在CTP中，VT尚未与更被认可的无氧阈值标志物乳酸阈值（LT）进行验证，本研究的目的是比较CTP组内以及CTP组与正常受试者（NL）之间的VT和LT。按照递增式跑步机方案，对10名男性原位CTP和10名年龄、体型及性别匹配的NL进行运动，直至症状受限的最大水平。使用V斜率法确定VT，使用对数-对数转换法识别LT。与CTP相比，NL在VT（1298.6±78.5 vs 919.0±57.2 ml·min⁻¹）和LT（1561.1±144.2 vs 921.6±47.6 ml·min⁻¹）时的绝对VO₂水平显著更高。然而，CTP与NL在VT（57.2±3.0 vs 49.0±3.5%）或LT（58.2±3.3 vs 58.5±4.9%）时的相对VO₂（%峰值）无显著差异。在各小组内，CTP（919.0±57.2 vs 921.6±47.6 ml·min⁻¹）或NL（1298.6±78.5 vs 1561.1±144.2 ml·min⁻¹）的VT和LT之间无显著差异。从本研究结果来看，VT似乎可作为CTP中LT的指标，且在临床应用可接受的范围内。（摘要截断于250字）
