Agostoni Piergiuseppe, Vignati Carlo, Gentile Piero, Boiti Costanza, Farina Stefania, Salvioni Elisabetta, Mapelli Massimo, Magrì Damiano, Paolillo Stefania, Corrieri Nicoletta, Sinagra Gianfranco, Cattadori Gaia
Centro Cardiologico Monzino, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Milan, Italy; Cardiovascular Section, Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy.
Centro Cardiologico Monzino, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Milan, Italy.
Chest. 2017 Jun;151(6):1329-1337. doi: 10.1016/j.chest.2017.01.009. Epub 2017 Jan 17.
Cardiac output (Q˙) is a key parameter in the assessment of cardiac function, its measurement being crucial for the diagnosis, treatment, and prognostic evaluation of all heart diseases. Until recently, Q˙ determination at peak exercise has been possible through invasive methods, so that normal values were obtained in studies based on small populations.
Nowadays, peak Q˙ can be measured noninvasively by means of the inert gas rebreathing (IGR) technique. The present study was undertaken to provide reference values for peak Q˙ in the normal general population and to obtain a formula able to estimate peak exercise Q˙ from measured peak oxygen uptake (V˙o).
We studied 500 normal subjects (age, 44.9 ± 1.5 years; range, 18-77 years; 260 men, 240 women) who underwent a maximal cardiopulmonary exercise test with peak Q˙ measurement by IGR. In the overall study sample, peak Q˙ was 13.2 ± 3.5 L/min (men, 15.3 ± 3.3 L/min; women, 11.0 ± 2.0 L/min; P < .001) and peak V˙o was 95% ± 18% of the maximum predicted value (men, 95% ± 19%; women, 95% ± 18%). Peak V˙o and peak Q˙ progressively decreased with age (R, 0.082; P < .001; and R, 0.144; P < .001, respectively). The V˙o-derived formula to measure Q˙ at peak exercise was (4.4 × peak V˙o) + 4.3 in the overall study cohort, (4.3 × peak V˙o) + 4.5 in men, and (4.9 × peak V˙o) + 3.6 in women.
The simultaneous measurement of Q˙ and V˙o at peak exercise in a large sample of healthy subjects provided an equation to predict peak Q˙ from peak V˙o values.
心输出量（Q˙）是评估心脏功能的关键参数，其测量对于所有心脏病的诊断、治疗及预后评估至关重要。直到最近，通过有创方法才能在运动峰值时测定Q˙，因此在基于小样本量的研究中获得了正常数值。
如今，可借助惰性气体再呼吸（IGR）技术无创测量运动峰值时的Q˙。本研究旨在提供正常普通人群运动峰值时Q˙的参考值，并得出一个能够根据测得的运动峰值摄氧量（V˙o）估算运动峰值时Q˙的公式。
我们研究了500名正常受试者（年龄44.9±1.5岁；范围18 - 77岁；男性260名，女性240名），这些受试者接受了最大心肺运动试验，并通过IGR测量运动峰值时的Q˙。在整个研究样本中，运动峰值时的Q˙为13.2±3.5升/分钟（男性15.3±3.3升/分钟；女性11.0±2.0升/分钟；P <.001），运动峰值时的V˙o为最大预测值的95%±18%（男性95%±19%；女性95%±18%）。运动峰值时的V˙o和运动峰值时的Q˙均随年龄增长而逐渐降低（分别为R = 0.082，P <.001；以及R = 0.144，P <.001）。在整个研究队列中，用于测量运动峰值时Q˙的由V˙o推导的公式为（4.4×运动峰值时的V˙o）+ 4.3，男性为（4.3×运动峰值时的V˙o）+ 4.5，女性为（4.9×运动峰值时的V˙o）+ 3.6。
在大量健康受试者中同时测量运动峰值时的Q˙和V˙o得出了一个根据运动峰值时的V˙o值预测运动峰值时Q˙的公式。
