Dept of Clinical Physiology, Lund University and Skåne University Hospital, Lund, Sweden.
J Cardiovasc Magn Reson. 2010 Dec 16;12(1):74. doi: 10.1186/1532-429X-12-74.
An early sign of heart failure (HF) is a decreased cardiac reserve or inability to adequately increase cardiac output during exercise. Under normal circumstances maximal cardiac output is closely related to peak oxygen uptake (VO2peak) which has previously been shown to be closely related to total heart volume (THV). Thus, the aim of this study was to derive a VO2peak/THV ratio and to test the hypothesis that this ratio can be used to distinguish patients with HF from healthy volunteers and endurance athletes. Thirty-one patients with HF of different etiologies were retrospectively included and 131 control subjects (60 healthy volunteers and 71 athletes) were prospectively enrolled. Peak oxygen uptake was determined by maximal exercise test and THV was determined by cardiovascular magnetic resonance. The VO2peak/THV ratio was then derived and tested.
Peak oxygen uptake was strongly correlated to THV (r2 = 0.74, p < 0.001) in the control subjects, but not for the patients (r2 = 0.0002, p = 0.95). The VO2peak/THV ratio differed significantly between control subjects and patients, even in patients with normal ejection fraction and after normalizing for hemoglobin levels (p < 0.001). In a multivariate analysis the VO2peak/THV ratio was the only independent predictor of presence of HF (p < 0.001).
The VO2peak/THV ratio can be used to distinguish patients with clinically diagnosed HF from healthy volunteers and athletes, even in patients with preserved systolic left ventricular function and after normalizing for hemoglobin levels.
心力衰竭（HF）的早期迹象是心脏储备减少或在运动期间无法充分增加心输出量。在正常情况下，最大心输出量与峰值摄氧量（VO2peak）密切相关，而 VO2peak 先前已被证明与总心脏容量（THV）密切相关。因此，本研究旨在得出 VO2peak/THV 比值，并验证该比值可用于区分 HF 患者与健康志愿者和耐力运动员的假设。回顾性纳入 31 例不同病因的 HF 患者，前瞻性纳入 131 例对照组受试者（60 名健康志愿者和 71 名运动员）。通过最大运动试验测定峰值摄氧量，通过心血管磁共振测定 THV。然后得出并测试了 VO2peak/THV 比值。
在对照组受试者中，峰值摄氧量与 THV 呈强相关性（r2 = 0.74，p < 0.001），但在患者中无相关性（r2 = 0.0002，p = 0.95）。即使在射血分数正常的患者中和血红蛋白水平正常化后，VO2peak/THV 比值在对照组受试者和患者之间仍存在显著差异（p < 0.001）。在多变量分析中，VO2peak/THV 比值是 HF 存在的唯一独立预测因子（p < 0.001）。
即使在左心室收缩功能正常且血红蛋白水平正常化后，VO2peak/THV 比值仍可用于区分临床诊断为 HF 的患者与健康志愿者和运动员。
