Department of Cardiology, Nihon University Hospital, Japan.
Healthcare R&D Center, Asahi Kasei Corporation, Japan.
Intern Med. 2024 Nov 1;63(21):2885-2893. doi: 10.2169/internalmedicine.2051-23. Epub 2024 Feb 12.
Objective Exercise therapy as part of cardiac rehabilitation is one of the most effective treatments for patients with chronic heart failure (HF). The anaerobic threshold (AT) determined by an exhaled gas analysis during cardiopulmonary exercise testing (CPX) is used to prescribe the appropriate level of exercise therapy. However, CPX using an exhaled gas analysis is not widely performed because of its cost, complexity, and the need for skilled staff. Therefore, a simpler and inexpensive method for determining AT without respiratory gas measurements is required in patients with HF. The present study elucidated the relationship between the AT determined by the CPX ventilatory method (CPX-AT) and the AT determined by cardiac acoustic biomarkers (CABs), which are measured by acoustic cardiography (CAB-AT), in HF patients. Methods Patients underwent symptom-limited ramp CPX twice using a cycle ergometer. The ATs determined from the exhaled gas analysis were identified by three independent physicians. CABs, including the first heart sound (S1) and the second heart sound intensities (peak-to-peak amplitudes), electromechanical activation time (EMAT) defined as the time interval from the Q wave onset on electrocardiography to S1, heart rate, and other parameters, were collected during CPX. Patients Forty patients with HF were included in this study. Results A significant correlation (R=0.70; p<0.001) was found between CPX-AT and CAB-AT, using the double product of S1 intensity and heart rate. CAB-AT using S1 intensity also showed a significant correlation with CPX-AT (R=0.71; p<0.001). Conclusion The present study suggests a possible new method for determining AT without respiratory gas measurements in patients with HF.
目的 运动疗法作为心脏康复的一部分，是慢性心力衰竭（HF）患者的最有效治疗方法之一。心肺运动测试（CPX）期间通过呼气气体分析确定的无氧阈（AT）用于规定适当的运动治疗水平。然而，由于其成本、复杂性和对熟练人员的需求，CPX 并未广泛采用呼气气体分析。因此，需要一种更简单、更经济的方法来确定 HF 患者的 AT，而无需进行呼吸气体测量。本研究阐明了 CPX 通气法（CPX-AT）确定的 AT 与心脏声学生物标志物（CAB）确定的 AT 之间的关系，后者通过声学心动描记术（CAB-AT）进行测量。
方法 患者使用自行车测力计进行两次症状限制斜坡 CPX。通过三位独立医生确定从呼气气体分析确定的 AT。在 CPX 期间收集心脏声学生物标志物（包括第一心音（S1）和第二心音强度（峰峰值幅度））、机电激活时间（定义为心电图 Q 波起始到 S1的时间间隔）、心率和其他参数。
结果 本研究共纳入 40 例 HF 患者。
结果 用 S1 强度与心率的乘积的双乘积，CPX-AT 与 CAB-AT 之间存在显著相关性（R=0.70；p<0.001）。S1 强度的 CAB-AT 也与 CPX-AT 有显著相关性（R=0.71；p<0.001）。
结论 本研究提示了一种在 HF 患者中无需进行呼吸气体测量即可确定 AT 的新方法。
