Miyagi K, Asanoi H, Ishizaka S, Kameyama T, Sasayama S
Second Department of Internal Medicine, Toyama Medical and Pharmaceutical University, Japan.
Clin Cardiol. 1993 Feb;16(2):133-7. doi: 10.1002/clc.4960160210.
Exercise tolerance was assessed in 146 patients with cardiac dysfunction in terms of anaerobic threshold (ATge). Patients were divided into four classes according to the peak oxygen uptake: Class A (72 patients) exceeding 1000 ml/min; Class B (27 patients) 800-999 ml/min; Class C (37 patients) 500-799 ml/min; and Class D (10 patients) below 500 ml/min. An incidence of the ATge breakpoint was lower in patients of Class C (38%) than in those of either Class B (70%, p < 0.05) or Class A (87%, p < 0.05). The ATge could not be determined in any patients in Class D. The V-slope method improved the ability to determine ATge by 20%. In Classes C and D, ATge detection was precluded considerably by the fact that the initial workloads of exercise test involved oxygen uptake levels already close to or above the ATge. An oscillatory hyperventilation pattern was also significantly related to failure in defining ATge in Class C patients. Of the 51 patients whose ATge was undetermined, 9 had an atrial septal defect. In two of these, exercise-induced right-to-left shunting led to progressive arterial hypoxemia, and the consequent hyperventilation masked the appearance of ATge. Thus, ATge is virtually undetectable in patients with severe heart failure largely because of the early onset of anaerobic metabolism or abnormal ventilatory responses to exercise. Accordingly, the clinical application of ATge in the assessment of functional capacity would be limited to patients with mild to moderate heart failure.
根据无氧阈值（ATge）对146例心功能不全患者的运动耐力进行了评估。根据峰值摄氧量将患者分为四类：A类（72例）超过1000 ml/min；B类（27例）800 - 999 ml/min；C类（37例）500 - 799 ml/min；D类（10例）低于500 ml/min。C类患者中ATge断点的发生率（38%）低于B类（70%，p < 0.05）或A类患者（87%，p < 0.05）。D类患者中无法确定任何一例的ATge。V - 斜率法使确定ATge的能力提高了20%。在C类和D类中，运动试验的初始工作量所涉及的摄氧量水平已接近或高于ATge，这一事实在很大程度上妨碍了ATge的检测。振荡性过度通气模式也与C类患者中无法确定ATge显著相关。在51例未确定ATge的患者中，9例患有房间隔缺损。其中2例运动诱发的右向左分流导致进行性动脉低氧血症，随之而来的过度通气掩盖了ATge的出现。因此，严重心力衰竭患者实际上无法检测到ATge，这主要是由于无氧代谢的早期发生或对运动的通气反应异常。因此，ATge在评估功能能力方面的临床应用将仅限于轻至中度心力衰竭患者。
