Nogami Yoshie, Seo Yoshihiro, Yamamoto Masayoshi, Ishizu Tomoko, Aonuma Kazutaka
Faculty of Engineering, Department of Human Environmental Sciences, Shonan Institute of Technology, Fujisawa, Kanagawa, Japan.
Department of Cardiology, Faculty of Medicine, University of Tsukuba, Tennodai 1-1-1, Tsukuba, Ibaraki, 305-8575, Japan.
Heart Vessels. 2018 Aug;33(8):931-938. doi: 10.1007/s00380-018-1138-0. Epub 2018 Feb 12.
Wave intensity (WI) is a novel noninvasive index of circulatory dynamics that reflects ventriculo-arterial coupling. It is calculated as the product of the first derivative of blood pressure and that of flow velocity measured by carotid echocardiography. This study aimed to clarify the clinical implications of WI and its relation with carbon dioxide production (VE/VCO slope). Twenty-one healthy volunteers (control group) and 21 patients with hypertension (HT group) underwent cardiopulmonary exercise testing (CPX) and exercise stress echocardiography. WI was assessed in the right carotid artery using an ultrasound system. The first peak of WI (W) during the early ejection phase was measured at baseline and mitral annular velocity was assessed by tissue Doppler imaging. Ventilatory kinetics during exercise was assessed using the relation of minute ventilation to VE/VCO slope. VE/VCO slope, W, and E/E' were greater in the HT group than in the control group. PeakVO and VO at the anaerobic threshold were lower in the HT group than in the control group. VE/VCO slope was significantly correlated with W (r = 0.58, p < 0.01) and E/E' (r = 0.44, p < 0.01). Stepwise multivariate analysis revealed that W was an independent determinant of VE/VCO slope (β = 0.43, p < 0.01). In conclusion, W might be able to predict the severity of heart failure without the need for CPX. Moreover, WI may be a useful modality in assessing heart failure pathophysiology based on ventriculo-arterial coupling.
波强度（WI）是一种反映心室 - 动脉耦合的循环动力学新型无创指标。它通过颈动脉超声心动图测量的血压一阶导数与流速一阶导数的乘积来计算。本研究旨在阐明WI的临床意义及其与二氧化碳产生（VE/VCO斜率）的关系。21名健康志愿者（对照组）和21名高血压患者（HT组）接受了心肺运动试验（CPX）和运动负荷超声心动图检查。使用超声系统评估右侧颈动脉的WI。在基线时测量射血早期WI的第一个峰值（W），并通过组织多普勒成像评估二尖瓣环速度。利用分钟通气量与VE/VCO斜率的关系评估运动期间的通气动力学。HT组的VE/VCO斜率、W和E/E'均高于对照组。HT组的无氧阈值时的峰值VO₂和VO₂低于对照组。VE/VCO斜率与W（r = 0.58，p < 0.01）和E/E'（r = 0.44，p < 0.01）显著相关。逐步多变量分析显示，W是VE/VCO斜率的独立决定因素（β = 0.43，p < 0.01）。总之，W可能无需CPX就能预测心力衰竭的严重程度。此外，WI可能是基于心室 - 动脉耦合评估心力衰竭病理生理学的一种有用方法。
