Bandera Francesco, Generati Greta, Pellegrino Marta, Donghi Valeria, Alfonzetti Eleonora, Gaeta Maddalena, Villani Simona, Guazzi Marco
From the Heart Failure Unit, IRCCS Policlinico San Donato, University of Milano, Milano, Italy (F.B., G.G., M.P., V.D., E.A., M.G.); and Unit of Biostatistics and Clinical Epidemiology, Department of Public Health, Experimental and Forensic Medicine, University of Pavia, Pavia, Italy (M.G., S.V.).
Circ Heart Fail. 2014 Sep;7(5):782-90. doi: 10.1161/CIRCHEARTFAILURE.113.001061. Epub 2014 Jun 26.
Several cardiovascular diseases are characterized by an impaired O2 kinetic during exercise. The lack of a linear increase of Δoxygen consumption (VO2)/ΔWork Rate (WR) relationship, as assessed by expired gas analysis, is considered an indicator of abnormal cardiovascular efficiency. We aimed at describing the frequency of ΔVO2/ΔWR flattening in a symptomatic population of cardiac patients, characterizing its functional profile, and testing the hypothesis that dynamic pulmonary hypertension and right ventricular contractile reserve play a major role as cardiac determinants.
We studied 136 patients, with different cardiovascular diseases, referred for exertional dyspnoea. Cardiopulmonary exercise test combined with simultaneous exercise echocardiography was performed using a symptom-limited protocol. ΔVO2/ΔWR flattening was observed in 36 patients (group A, 26.5% of population) and was associated with a globally worse functional profile (reduced peak VO2, anaerobic threshold, O2 pulse, impaired VE/VCO2). At univariate analysis, exercise ejection fraction, exercise mitral regurgitation, rest and exercise tricuspid annular plane systolic excursion, exercise systolic pulmonary artery pressure, and exercise cardiac output were all significantly (P<0.05) impaired in group A. The multivariate analysis identified exercise systolic pulmonary artery pressure (odds ratio, 1.06; confidence interval, 1.01-1.11; P=0.01) and exercise tricuspid annular plane systolic excursion (odds ratio, 0.88; confidence interval, 0.80-0.97; P=0.01) as main cardiac determinants of ΔVO2/ΔWR flattening; female sex was strongly associated (odds ratio, 6.10; confidence interval, 2.11-17.7; P<0.01).
In patients symptomatic for dyspnea, the occurrence of ΔVO2/ΔWR flattening reflects a significantly impaired functional phenotype whose main cardiac determinants are the excessive systolic pulmonary artery pressure increase and the reduced peak right ventricular longitudinal systolic function.
几种心血管疾病的特征是运动期间氧动力学受损。通过呼出气体分析评估，氧耗量（VO2）/工作率（WR）关系缺乏线性增加被认为是心血管效率异常的一个指标。我们旨在描述有症状的心脏病患者群体中VO2/WR变平的频率，表征其功能特征，并检验动态肺动脉高压和右心室收缩储备作为心脏决定因素起主要作用的假设。
我们研究了136例因劳力性呼吸困难而转诊的患有不同心血管疾病的患者。使用症状限制方案进行心肺运动试验并同时进行运动超声心动图检查。36例患者（A组，占总人群的26.5%）观察到VO2/WR变平，并且与整体较差的功能特征相关（峰值VO2降低、无氧阈值、氧脉搏、VE/VCO2受损）。单因素分析时，A组的运动射血分数、运动性二尖瓣反流、静息和运动时三尖瓣环平面收缩期位移、运动时收缩期肺动脉压和运动时心输出量均显著受损（P<0.05）。多因素分析确定运动时收缩期肺动脉压（比值比，1.06；置信区间，1.01-1.11；P=0.01）和运动时三尖瓣环平面收缩期位移（比值比，0.88；置信区间，0.80- .97；P=0.01）是VO2/WR变平的主要心脏决定因素；女性与之密切相关（比值比，6.10；置信区间，2.11-17.7；P<0.01）。
在有呼吸困难症状的患者中，VO2/WR变平的出现反映了一种明显受损的功能表型，其主要心脏决定因素是收缩期肺动脉压过度升高和右心室纵向收缩功能峰值降低。
